Science in the box

Soap
If prehistoric man cleaned himself or his clothing, he only used water.
Baths
Prehistoric people may have learned from experience that eating with dirty hands could be dangerous and often fatal. This may have led them to wash their dirty hands in water, providing the first example of washing having an impact on human health. With the discovery of fire about 1.8 million years ago, it’s possible that water was heated for washing.
Water supply
Early man lived near rivers and streams, and used the water for drinking.
Human waste
People living in small societies, such as families or small tribes, usually defecated privately near a stream or somewhere far enough away from where they lived that the smell wouldn’t bother them. When it came to Neanderthal man, this often took place deep inside a cave. This became a health problem once populations grew and some cultures became sedentary.
Environmental impact
Since prehistoric man lived in a small group or community, and was primarily concerned with activities needed for survival (hunting and gathering food), the environmental impact of human activity was small and, in a sense, hardly different from the impact of groups of animals. Any wastes that were generated would have degraded quickly. The human population density was far below the carrying capacity of the environment.
Further reading

• De Bonneville, Francoise (1998). The Book of the Bath. Rizzoli Publ. Stalmans, M. & Guhl, W. (2003). An Introduction to the Historical Developments of Laundry. Household and Personal Care Today, pp. 17-22.
• Ostia Antica web site – http://www.ostia-antica.org/

Soap






The first primitive soap was made from ashes from wood and other plants, by extraction with water. Ashes from halophytes – plants from the Mediterranean region - such Saponaria sp., Salicornia sp. and Salsola sp., were particularly effective for soap-making. The fact that such alkaline solutions had cleaning properties was probably discovered accidentally. According to legend, the word soap, or rather the process of saponification, derives from Sapo Hill in Rome, where animals were sacrificed and cremated. Tallow, or animal fat, and ash were washed down the hill by rainwater, into the clay soil along the Tiber River. Women found that washing clothes was easier if they used this clay. A less romantic derivation is the name of the Italian town of Savona, where large quantities of soap were manufactured during the 9th century A.D. In French, “savon” means soap. The oldest reference to purposeful soap-making dates back to 2800 B.C. Fats were boiled with ashes to make soap. Gallic and Germanic tribes carried out saponification by trial and error. In the process of soap-making, they also produced glycerol as a result of the action of alkali on fat (goat tallow, birch wood ash and herbal extract colouring). Human or animal urine was commonly used as a cleaning agent in ancient times. Its cleaning properties are due to the production of the alkaline ammonium carbonate from fermentation of urea. Its use was first reported in the Orient, from which it spread to the West.
Baths
The first Roman baths were built around 312 B.C. and continued to be popular until the fall of the Roman Empire in the 6th century. At the end of the day, Roman men and women would gather at the public bathhouses. Some wealthy families had their own bathhouses, yet they would often invite friends to bathe with them, as bathing was very much a social event. Afterwards, they would spend the rest of the evening on an elaborate dinner. When the Roman Empire fell in 467 A.D., their habits with regards to personal cleanliness were also lost. In the Middle Ages, this lack of hygiene would have dramatic consequences. The ancient Greeks “washed” themselves with lumps of clay, had steam baths and rubbed their skin with oil, such as olive oil, which they then scraped off with an instrument called a “strigil”, along with any dirt. The use of soap for bathing was reported as early as 1500 B.C. by the ancient Egyptians.
Laundry
Frescoes in Pompeii show how important laundry was for the Romans. Laundry was not done at home, at least not by the wealthier Romans. It was done at the public “fulleries” – the equivalent of the modern laundromat – by workers called “fullones.” “The large fulleries have several features in common. They contain a large hall with very large basins in the floor, communicating with one another. In these basins clothes were put to soak and cleaned. Along three sides of the hall are pressing-bowls, usually made of terracotta, often the lower half of a dolium. Here the material was further cleaned, by workers who ’jumped‘ or ’danced‘ on the clothes (the so-called saltus fullonicus; Seneca, Epistulae 15,4), while they leaned on small walls on either side. Detergents were used, such as the creta fullonica (fuller’s earth), that was stored in small bowls. It helped remove the grease and enhanced the colours. Urine, collected in public urinals, was used for bleaching, and so was sulphur, which was burned under wooden frames over which the cloth was suspended.

After the pressing, the material was taken to the basins again, for the removal of the detergents. Fullers were organized into powerful guilds. Clothes were cleaned by treading (fulling) in stone bowls containing clay and ammoniated water. After rinsing once, the bowls were filled once more and the clothes were rinsed again. Drying took place on bell-shaped wire frames under which sulphur was burned” (from the Ostia Antica website).
The Roman laundries were not a healthy work environment: workers were constantly exposed to polluted, foul-smelling air and their skin was in constant contact with chemicals in the water. As a result they ran a high risk of developing work-related illnesses.
Water supply
During the early years, water for Rome was brought in from the Tiber River. Aqueducts that piped the water from rivers or wells into the city were built during the Late Empire. Wealthy Romans had the water piped all the way into their homes, but most people had to rely on the public fountains or water delivery by a contractor or Aquarius. Some homes had cisterns in which rainwater was collected. The aqueducts and cisterns of Carthage (Tunisia) are well preserved to this day.
Plumbing
Rome was well equipped with open drains and sewers, which ran parallel to streets. Many houses had latrines, but apartments did not. Where there were no latrines, chamber pots were used. These were emptied in the public drains and sewers, or in public urinal pots. The large public urinal pots at the street corners were periodically emptied by “fullers” who worked in the laundry facilities, where urine was used as a laundry additive. Public toilets were large, rectangular rooms that could be used by many people at the same time. The construction was similar to today’s “outhouses,” but the waste was continuously flushed away by running water in the sewers down below.
Environmental impact
Since prehistoric man lived in a small group or community, and was primarily concerned with activities needed for survival (hunting and gathering food), the environmental impact of human activity was small and, in a sense, hardly different from the impact of groups of animals. Any wastes that were generated would have degraded quickly. The human population density was far below the carrying capacity of the environment.
Fabrics
Men and women of Rome were very interested in fashion. They wore tunics, which were knee-length for the men and floor-length for the women. Heavy white togas were worn on formal occasions. The fabrics of the time were wool, linen, silk and cotton. The women wore make-up and jewellery, mostly gold and precious stones among higher classes, amber jewellery among lower classes.
Further reading

• De Bonneville, Francoise (1998). The Book of the Bath. Rizzoli Publ. Stalmans, M. & Guhl, W. (2003). An Introduction to the Historical Developments of Laundry. Household and Personal Care Today, pp. 17-22.
• Ostia Antica web site – http://www.ostia-antica.org/

Soap
In the Middle Ages, soap was used primarily for washing clothes. Arab traders brought bars of soap to Europe in the 7th century, and soon soap-making became an established craft in Europe. Soap-makers formed guilds and jealously guarded their recipes. Soap production began to differ from region to region. In southern European countries, such as Italy, Spain, and southern France, soap was made from olive oil. During this period, Castile soap began to be made in Spain. In the countries of northern Europe, soap was made from a base of animal fats, primarily tallow from cattle, and sometimes even from fish oils. Aromatic herbs were added for fragrance. The soaps made from olive oil were of a higher quality than those made from animal fats, and soap manufacturers in the south began to export their products to other countries. In the 9th century, Marseille, Geneva, Savona, and Venice became important centres of soap manufacturing. These regions had a plentiful supply of olive oil and the barilla plant, the ashes of which were used to make lye. During the 10th century, soap production expanded to many European cities. By the 12th century, soap started to be produced in England where the soap business was very successful and would remain so for centuries to come. In 1622, King James I granted a monopoly to a soap-maker for $100,000 a year! Until the 19th century, soap was a heavily taxed luxury item in most countries, and therefore out of reach for the ordinary citizen.
Baths
In Europe, cities had public baths, called stews, where two or three patrons at a time bathed together in large wooden tubs. The aristocracy had their own private baths, and even tiled rooms devoted to bathing. But early in the Middle Ages, the practice of bathing declined, as people began to believe that it spread epidemics. But because people also believed that bad odours spread disease, they made liberal use of perfume.
Laundry
Clothing was washed only every two or three months. It was soaked in a tub with a washing solution of lye and fuller’s earth or white clay. Then it was trampled or beaten, after which the dirty wash water ran out through a hole. This process was repeated until the water came out clean, after which the clothes were rinsed, wrung out by hand, and left to air dry.
Water supply
Wealthier citizens and the aristocracy had water piped into their homes or castles, and peasants used public fountains or wells. Because of nonexistent sanitation, drinking water was often contaminated. Wastewater was discarded directly into the streets.
Human waste
Chamber pots were used to contain human waste, and the contents were emptied into the streets. Some cities had laws requiring people to call out a warning before emptying pots, to avoid unpleasant accidents. In many homes, the first floor had a protuberance in the back, and feces were collected from there.
Environmental impact
Especially in cities, the environmental impact of human activity was very high. Waste was discarded into the streets, where it sat for days before it was washed untreated into rivers and streams.
Fashion
Most people in the Middle Ages wore woollen clothing over undergarments made of linen. The wealthy wore garments with brighter colours, made from better materials. Toward the end of the Middle Ages, clothing became more elaborate. Wealthy men wore hose and a jacket, often with skirting, and aristocratic women were partial to flowing gowns and headdresses shaped like hearts or butterflies or tall steeple caps.
Further reading
De Bonneville, Francoise (1998). The Book of the Bath. Rizzoli Publ. Stalmans, M. & Guhl, W. (2003). An Introduction to the Historical Developments of Laundry. Household and Personal Care Today, pp. 17-22.

Soap
Soap making became more specialized. In the 15th and 16th centuries in France, soap was made on a small scale from goat tallow and beech ash, but in the 17th century, soap factories were established. The first one, built by royal edict in Toulon, was an immediate success. More factories were built in Marseille. By the end of the century, Marseille had to import raw materials from all over the Mediterranean to keep up with demand, and the French perfected the soap manufacturing process, now using vegetable oils rather than animal fat. All along, soap was used for laundry. Towards the end of the Renaissance, soap came back into favour for bathing, and people began to use soap for shaving and shampooing.
Baths
Throughout much of the Renaissance, people believed that water penetrated the skin and spread disease. Indeed, King Louis XIII had what was only his second bath at the age of 7, and Louis XIV took baths only when it was prescribed as a medical treatment. It was thought that a layer of dirt protected the body, so people cleaned themselves by rubbing exposed parts of the body with a dry, sometimes perfumed, cloth. To show that they were “clean,” the nobility wore white linen shirts, and changed them daily. In 1626, Savot, a French etiquette writer, wrote, “We can more easily do without [baths] than the ancients, because of our use of linen.” In the mid-17th century, clothing got a dusting of scented powder to make it smell fresh longer, and after this, nobles no longer felt the need to change clothing so often. This lack of hygiene started to change toward the end of the Renaissance. Body odours became less tolerated, and cleanliness became more important. Communal bathing in bath houses became popular once again (as it once was in Rome) and was often accompanied by music and eating. But because nudity was taboo, people wore clothes while bathing. As a courtesy, people offered a bath to their guests, and by the 15th century, this was an established part of the code of hospitality. Hand washing before and after eating is often mentioned in literature from this period, and basins appear regularly in illustrations. During the 14th and 15th centuries, washing one’s hands became an elaborate ceremony at banquets, complete with a servant called the Laverer, who brought water and towels to guests before a feast began. Outside Europe, regular bathing was the custom. In India, the institution of Gushalkhana (a bathroom) was established by the Mughal Kings in 1556. Oppressed by the heat and dust, the Kings constructed luxurious bathing and massage facilities, but these were accessible only to the rich. Indian handbooks from the 17th century describe bathing rituals that took place in bathing ghats, public baths on a riverbank.
Laundry
There were a large number of laundries in cities because of the importance of keeping linen white, but women also did laundry at home and it continued to be backbreaking labour. Clothes had to be soaked, boiled and beaten, then rinsed and wrung out by hand, and dried in the fresh air. Washboards and sticks made doing the laundry a little easier, but it was still a very time-consuming task. Leftover soapy water was given to the poor, because soap was still too expensive for most people. In addition to the regular laundry, a “Grand Wash” took place twice a year. It was a symbolic ritual, lasting three days. Some sources say that that it represented Hell, Purgatory, and Paradise. The “Grand Wash” was a symbol of purification, the triumph of clean over unclean. Communal laundry rituals also existed in Asia and North and South America.
Water supply
Throughout the Renaissance, little progress was made in terms of bringing the water to the people. Water could only be moved around by mechanical means. The homes of the wealthy and certain centres of culture, such as monasteries, had water piped in, but the poor still had to hand-carry their water home from wells and rivers. In 1698–99, the steam engine was invented by Thomas Savery and Thomas Newcomen. It would later be perfected by James Watt and Benjamin Franklin. This invention would lay the groundwork for the water distribution networks of the future.
Plumbing
Chamber pots continued to be used throughout the period, but now small rooms or closets were dedicated to the purpose of using these chamber pots in private, hence the terminology “water closet” and “privy.” The contents of the pots had to be hauled away manually. In 1596, Sir John Harrington, godson to Queen Elizabeth, installed water closets for the queen and himself. However, he was ridiculed by his peers for this device, and never built another one.
Environmental impact
Pollution continued to be a problem, due to the increasing population in cities. Waste water from household uses and laundries, as well as human waste, continued to be discharged into rivers and streams without any type of treatment.
Fashion
Clothing during the Renaissance was very important to the aristocracy, because it demonstrated one’s cleanliness and wealth. Girls wore many layers of clothing: a chemise, stockings, a leather corset, a bodice, and petticoats, topped by a gown. Both girls and women covered their hair with a scarf or hat. Boys dressed like their fathers, with shirts and a fitted jacket, hose and breeches. Clothes were made out of wool, cotton, raw silk, linen, flax, leather or linen. Coloured fabrics were rare and for the most part only the rich could afford them; purples and reds were very difficult to obtain and reserved for royalty exclusively.
Further reading
• Bramsky, S. & Reynolds, S. (1995). Leonardo: The Artist and The Man. Penguin Publishers, USA.
• De Bonneville, Francoise (1998). The Book of the Bath. Rizzoli Publ.
• Stalmans, M. & Guhl, W. (2003). An Introduction to the Historical Developments of Laundry.Household and Personal Care Today, pp. 17-22.

Soap
At the beginning of the 18th century, Marseille had around 15 soap factories, making it the Mediterranean centre for production and distribution of soap made from olive oil and natural soda. Also in the 18th century, and continuing at the beginning of the 19th century, soap was heavily taxed as a luxury product. When taxes were lowered and advances in chemistry integrated in the soap-making process, soap became an everyday item for the majority, with a resulting rise in cleanliness standards. In 1837, two young men merged their two businesses, a candle factory and a soap manufacturing business, into The Procter & Gamble Company. In the United States, scientific discoveries allied with the overall industrial potential of the country made soap manufacturing one of the nation’s most flourishing industries from 1850 onwards.
Baths
Throughout the 18th century, the belief that originated during the time of the plague in the Middle Ages, namely that disease could be contracted through water that touched the skin, remained relatively unchallenged. The world would have to wait until the mid-19th century for French scientist Louis Pasteur to prove this theory wrong. Until then, bathing was used as a medical treatment in thermal springs, a leisure activity for the upper class at the health spas, and as a status symbol for the upper class generally.
Advances in science and technology
In 1774, Swedish chemist Karl Wilhelm Scheele discovered chlorine. Scientists would later discover that, mixed with water, chlorine bleaches (Claude Berthollet) and that, mixed with a soda solution, chlorine disinfects (Antoine Labarraque). In 1783 Karl Wilhelm Scheele discovered a sweet-tasting substance he called OÅNlsüss (which we now know as glycerol or glycerin) by boiling olive oil with lead oxide.

Soap manufacture was revolutionized in 1791 by the chemist Nicolas Leblanc, who devised a process of obtaining sodium carbonate (washing soda) from sodium chloride (salt). Soap is produced from soda and fat. Leblanc’s process resulted in the production of large quantities of good quality and low-cost soda. In 1823, inspired by this discovery, French chemist Eugène Chevreul found that soap is not formed by fats combining with alkali, but that these are first broken down into fatty acids and glycerol. Chevreul thus originated the theory of saponification. Towards 1840 the process evolved further by the use of oils other than olive oil, resulting in a still greater variety of end products. Chevreul’s discovery revolutionised the candle industry. Another important leap forward was made when Belgian chemist Ernest Solvay (1838 – 1922) discovered that soda (sodium carbonate) could be produced on a larger, commercial scale from ammonia, carbon dioxide and salt (sodium chloride). The Solvay Process resulted in better quality soda produced at a lower cost. On a different front, Frenchman Louis Pasteur (1822 – 1895) proved the link between micro-organisms and infectious diseases with his famous “germ theory.” As of that moment, the importance of hygiene for the protection of public health became a firmly established fact.
In 1879, William Procter invented Ivory Soap.
In 1889, Gottlieb Daimler and Karl Benz invent the automobile, revolutionizing transport, which would have far reaching consequences for all of industry.
Laundry
The middle of the 19th century witnessed the appearance of the first mechanical washing machines.
Typically a closed tub with wooden paddles (agitators, later made of metal) allowed laundresses to work in an upright position and not get their hands wet so much. Laundry was no longer the laborious and time consuming ritual it had been in the past. The dirt and bad smells that accompanied overcrowding in the cities were less and less acceptable to people, and this led to steady scientific progress. But before washing machines were generally in use, large towns installed large public wash-houses or laundries. The fixed tub with a hand-propelled rotating agitator was the forerunner of the rotating tub (gyrator) machine. The forerunner of the modern drum machine that extracts the water during a rapid spin cycle would not appear until into the 20th century. Laundry remained a ritual in the U.S. throughout the 19th century. A written testimony by a late-19th century author in Practical Housekeeping reads: “Laundry and cooking go hand in hand… On washing and ironing days, it is inadvisable to cook steak or fry fish, due to the smell. In addition, no spinach, split peas, green beans (which need stringing), or stewed apples [should be prepared] because these all take too long to prepare and time should be given to the laundry. More suitable dishes would be potatoes, pasta, rice and corn, with a dessert of baked apples with cream: Quick, easy and very tasty.” Developments in laundry products didn’t keep pace with the technological advances in washing machines: Until the end of the 19th century, people still washed their clothes with soap flakes. Synthetic detergents would not appear for another 10 to 20 years, during World War I.
Water supply and indoor plumbing
The wealthy had water piped into their homes, but for the urban poor, water hydrants or street pumps provided the only source of water. To make matters worse, these were opened infrequently and not always on schedule. In the countryside, people still drew water from rivers or wells. In 1829 and 1834, architect Isaiah Rogers built the Tremont Hotel in Boston and the Astor House in New York, both with indoor plumbing and bathrooms in every room. A storage tank on the roof supplied the bathrooms, kitchen and laundry with running water. Baths were copper or tin tubs, and the water for the bath was heated in small gas furnaces. A steam engine-driven pump raised the water to the storage tank on the rooftop. A simple system of pipes transported wastewater to the sewers. By the middle of the 19th century, the more widespread installation of sewers in the cities provided more people with a way to dispose of their wastewater. In 1652, Boston had already built the first public waterworks in the U.S., formed to provide water for fire fighting and domestic use. Wooden pipes were used until the early 1800s when the switch was made to cast iron. Later - in the 20th century - cement, concrete, steel and iron would be used for the water distribution lines. In 1857, engineer J. W. Adams’ designs laid the groundwork for modern sewer systems. In 1869, Chicago drew water from Lake Michigan via a tunnel. Steam engines pumped the water from the tunnel beneath the lake. In 1906 the system was modernized. This station is still supplying Chicago with water until this day. Chicago also was the first city to install a citywide sewerage system in 1885. By the mid-1850s, many new homes had bathrooms. Copper and silver fixtures made room for stainless steel. Lead pipes were used for cold-water supply lines, but were later replaced with iron, copper and sometimes even plastic. In the late 1730s, the valve-type toilet came into use. The valves were rudimentary, however, and often leaked. By the late 1770s, the hydraulics were improved, and this type of toilet is still in use today in many areas. There was another major breakthrough around 1820, with the invention of the flush-type toilet by Albert Giblin in Britain. This was a siphon toilet with a water reservoir for flushing when a rope was pulled. A certain Thomas Crapper worked on developing the piping of toilets, but contrary to popular legend, he didn’t invent the flush toilet. His name, however, lives on in the slang for “toilet.” In 1857, toilet paper was invented by the American Joseph Cayetti. In Asia, the wealthy already had toilet-like devices when in the early 18th century. Soon, the cheaper European toilets began to appear in the homes of the less well off.
Environmental impact
All household waste waters, including the spent wash water (grey water) and water containing human waste (black water), were discharged into the rivers and surface waters without any form of prior treatment. Regulations to protect the environment did not yet exist. The second half of the 19th century witnessed the onset of the industrial era. Inevitably, environmental pollution kept right in step with it, until public awareness and environmental regulation would catch up – but that would not happen until much later, about the middle of the 20th century.
Fabrics
Clothing became more elaborate for both men and women. Women layered on a chemise, a corset, numerous petticoats, and a dress. Men wore breeches or trousers, shirts, waistcoats, and coats, often with embroidery. For both men and women wore clothing made of silk, satin, velvet, wool, and cashmere.
Some famous scientists of the 18th and 19th centuries
Nicolas Leblanc - French chemist (1742-1806), perfected a process for preparing sodium carbonate, contributing to the development of the use of minerals in the chemical industry. Karl Wilhelm Scheele - Swedish chemist, born in Stralsund (1742-1786). Discovered chlorine, glycerol and hydrocyanic (prussic) acid.
Hydrocyanic acid: Hydracid, HCN, intermediary in numerous reactions, but also highly toxic. Antoine Labarraque - Chemist and pharmacist, born 1777 in Oloron (France), died in Paris 1850. Discovered disinfectant properties of bleach. Labarraque solution: A solution of sodium hypochlorite and water in equal measures. Used to disinfect objects, but not advisable for wounds. Other uses include deodorising and bleaching.
Count Claude Berthollet - French chemist born 1748 in Talloires (France), died in 1822 in Arcueil. He discovered hypochlorites and applied their bleaching properties to cloth. He also perfected chlorate-detonated explosives, and went to Egypt with Napoleon Bonaparte.
Hypochlorite: Salt of hypochlorous acid (sodium hypochlorite is a constituent of “Eau de Javelle,” or common household bleach).
Eugène Chevreul - French chemist born 1786 in Talloires, died in 1889 in Paris. Noted for his research in organic chemistry, particularly the composition of fats, necessary to understand saponification. He also worked on the theory of colour contrasts, and the results of his studies influenced the neo-impressionist painters. Saponification: A chemical reaction from an ester molecule, yielding a carboxylase ion, a conjugated base of carboxylic acid and an alcohol. Ernest Solvay - Belgian industrialist, born in Rebecq-Rognon (Belgium) (1838-1922). Founder or benefactor of various scientific bodies, he originated a manufacturing process for sodium carbonate whereby a concentrated solution of sodium chloride is saturated with ammonia, carbon dioxide is passed through it, and the product is calcinated (1861-1865).
Further reading
• De Bonneville, Francoise (1998). The Book of the Bath. Rizzoli Publ.
• Practical Housekeeping. A Careful Compilation of Tried and Approved Recipes. Minneapolis, MN: Buckaye Pub. & Co., 1884.
• Stalmans, M. & Guhl, W. (2003). An Introduction to the Historical Developments of Laundry. Household and Personal Care Today, pp.17-22.

Soap and synthetic detergents
During the the World Wars, in particular World War II, detergent research was spurred by shortages of animal and vegetable fats, plus the need for armies to wash clothes in hard, cold water. The first detergents were mainly used for dish washing and laundering delicate fabrics. From the 1950s onwards, soap products were gradually replaced by synthetic detergents derived from petroleum by-products, vegetable oils and animal fats. Development of all-purpose detergents began in 1946, when the first detergents that contained surfactants and builders were introduced in America (“built” detergents). This combination of ingredients worked very well because the surfactant would remove the dirt, whereas the builder would make the surfactant more effective. Synthetic surfactants held a significant performance advantage over soap: they performed much better in cold, hard water. Synthetic detergent production surpassed the highest level ever achieved by soap in 1957. Detergents could now be found in many common household products, including personal hygiene products, and progress has continued at a rapid pace ever since. In 1964, biodegradable LAS (linear alkylbenzene sulfonate) replaced branched alkylbenzene sulfonate, its non-biodegradable counterpart. The worldwide consumption of detergents and soap today (2003) is more than 27 million metric tonnes. Soap accounts for 9 million tonnes.
Laundry
The first electric washing machine was produced in the U.S. in 1908. It featured a top-mounted electric motor-driven agitator. Towards 1920, new machines were fitted with a horizontal cylinder. But this did not prevent manual machines from prospering. At the end of the 1940s, electric machines were fitted with an impeller. During the 1950s, a heating element and automatic spin cycle were added (some machines had separate spinners, alongside the wash drum). The 1960s saw the advent of automatic machines which, at the touch of a button, wash, rinse and spin in the same drum, at first mounted vertically, and later horizontally (“front loaders”). By the end of the 20th century, washing machine technology had continued to evolve. Electro-mechanical controls (knobs) had been replaced by electronic ones (push-buttons). The newer machines required less water and newer laundry products worked better at lower temperatures, rendering the laundry process more energy-efficient. Concentrated laundry products required less transport, less shelf-space and less packaging. New wash cycles appeared, such as those for silk, wool and delicates, and short wash. In some developing countries, even today, manual practices still exist, as shown in these photographs of people in India, doing the laundry on the banks of the Ganges, and of people on the African continent.
Water supply and indoor plumbing
As the 20th century progressed, indoor toilets and running water—often both hot and cold—became the norm, especially in cities. In rural areas, however, outhouses continued to be used, in some areas until the 1960s. Beyond that, most communities in developed countries had main water supplies and sewage systems. At the start of the 21st century, the trend in bathrooms was to make them bigger and more luxurious. Bathrooms no longer consist of just a standard toilet, sink, and bathtub/shower combination. New bathrooms are large, tiled rooms with a toilet and a bidet, two or more sinks, a stand-alone shower, and a roomy bathtub, often with a whirlpool bath. The poor in some developing countries, however, must still haul water from a communal tap - water which is not guaranteed safe to drink - and share communal toilets. In many countries outside Western Europe and North America, running water that is piped into the home may not be safe to drink, and may need to be boiled or chemically treated.
Environmental impact
Centralized wastewater treatment emerged in the form of municipal sewage treatment works in the late 19th and 20th centuries in the cities of the U.K. and the United States. There are, by origin, three types of wastewater: storm water from runoff after rains, sanitary or domestic wastewater from homes and industrial waste water. Early sewage treatment works would accept all three types, but ran into problems with overflow and too highly polluted industrial wastewaters. After 1950, as public concern about the environment increased, the number of regulations designed to protect the environmental also increased. In modern sewage treatment systems, storm waters by-pass the treatment works and are discharged directly to surface waters. Domestic wastewater is treated at the municipal sewage treatment plant and then discharged. Manufacturers are often required to pre-treat their wastewater prior to sending it to a municipal sewage treatment plant. Detergent manufacturers started developing biodegradable detergents in the 1960s. These detergents contain surfactants and other cleaning agents that are effectively removed from wastewater during sewage treatment. However, not all countries can afford the luxury of wastewater treatment, even though it is badly needed and often required by law. When wastewater treatment is not available, sewage is discharged directly into surface waters which causes pollution even today. It has been shown that the development of modern wastewater treatment significantly improves the quality of surface waters. Since detergent and cleaning product ingredients are well removed during wastewater treatment, there are no adverse ecological effects from the use of laundry detergents and household cleaning products.
Fabrics
During the late 19th and 20th centuries, man-made fibres were developed. Until then, fabrics were made from natural fibres: cotton, wool, silk, jute or flax. Synthetic fibres (nylon, polyethylene terephtalate, acrylics, polyurethane, polypropylene) were manufactured from polymers, made from petroleum by-products or natural gas. The first women’s nylon stockings caused quite a stir in 1940! Fabrics from synthetic fibres were cheaper to make, easier to dye and offered more processing flexibility compared to the natural fabrics. Also the characteristics of the fabric could more easily be tailored for certain purposes: think about the revolution in outdoor wear and sportswear in the 1990s, with fleece, Polartec®, wrinkle-free fabrics, water-repellent fabrics, stain-resistant fabrics, thermal fabrics, breathable fabrics - the list goes on and on. These rapid developments in the textile industry put pressure on the fabric care industry to keep up, as people needed affordable technology to take care of an ever expanding range of fabrics. In addition, the customers of the late 20th and 21st centuries, often part of dual-career families, don’t want to spend a lot of time on laundry, and they want their clothes to stay looking newer, longer.
Further reading
• De Bonneville, Francoise (1998). The Book of the Bath. Rizzoli Publishing.
• Stalmans, M. & Guhl, W. (2003). An Introduction to the Historical Developments of Laundry. Household and Personal Care Today, pp. 17-22.
• Encyclopædia Britannica (2003). Man-made Fibre. Encyclopædia Britannica Premium Service.

The early history of washing is described in the history of laundry. To read about this, please refer to our www.scienceinthebox.com page.