cotton

A Travelling Botanist: The worlds most used fibre!

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Guest blog series by: Sophie Mogg

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Gossypium aboreum flower

Cotton, we’ve all seen it, heard of it and probably worn clothes made from it too. In today’s installment we’ll be taking a look at Gossypium arboreum, the species of cotton native to India and Pakistan. This particular species was supplied as a single specimen by Carl Linnaeus for his herbarium and was recorded within his own book,  Species Plantarum 1753.

Cotton has been cultivated in South Asia from around 3300 BCE. It is a perennial shrub, reaching approximately 2M tall and grown more like an annual due to being harvested every year. The leaves of the cotton plant are lobed, typically having 3-5 lobes and bearing a close resemblance to maple leaves.  The seeds are contained within the boll, a small capsule and individual seeds are surrounded by two types of fibres known as staples and linsters. The former is produced into high quality textiles where as the latter produces lower quality textiles. Whilst Gossypium arboreum and its sister plant, Gossypium herbaceum (Africa) only form 2% of the world production of cotton, new varieties of these species are being bread for more desirable traits. One such variety is Gossypium arboreum var. neglecta grown along the Meghna river. This variety, known as “Phuti karpas” is used to make Muslin in Bangladesh as the cotton fibres  can be spun to produce threads are more resistant to breaking at higher counts.

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Specimens of cotton at different stages of processing. Gossypium herbaceum (Africa) bolls.

The fibres can be separated from the seeds either manually or by use of a machine known as the cotton gin. There are two types of cotton gins, the saw gin for the shorter fibres and roller gin for the longer fibres. The roller gin was invented in India and is used to prevent damage to the longer fibres. Once fibres are separated from the seed they are compressed  into lint bales and graded. Carding is the next step, where fibres are pulled so that align parallel to one another and eventually form a sliver which is a rope-like strand of cotton. The slivers are combed to remove impurities before being drawn out into thin strands (roving). The final processing step of cotton is the spinning, where the roving is drawn out and twisted for form yarns and threads for weaving to produce textiles.

Towards the end of the 18th century Manchester had begun to build steam powered mills in order to work with cotton and by 1871 was using approximately 30% of the cotton produced globally. Over 100 cotton mills were built during this time and the industry was supported by The Exchange where over 10,000 cotton merchants would meet in order to sell their wares. The start of the cotton industry across Britain coincided with the Calico act of 1721 being repealed allowing British companies to use cotton in order to make calico, a cheaper and less refined cotton textile, into clothing. Cotton textiles soon became one of the main exports of Britain and is still one of the worlds most used fibres today.

If you are interested in finding out more about plants from Asia over the next few weeks please fill out the poll below.

 

If you would like to learn more about cotton and the cotton industry follow the links below:

Cotton Industry

Cotton Processing

Gossypium arboreum

Uses of Cotton Seed

I’ll soon be travelling to other parts of Asia so I hope you continue to join me. Look for future blogs exploring dyes, medicines and potentially poisons. As always, don’t forget to leave a comment about what you’d like to see from our collection.

A history of cotton

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by Jemma

 

So after my blog on the opium poppy (https://herbologymanchester.wordpress.com/2015/01/23/powerful-poppies/) I have decided to write another; this time on Gossypium barbadense.

Gossypium barbadense seeds from the Materia Medica.
Gossypium barbadense seeds from the Materia Medica.

 

G. barbadense is a small, tropical tree that produces cotton. The cotton fibres grow in a protective capsule, called a boll, around the seeds to increase seed dispersion. These fibres can be collected and spun into yarn or thread, which then have a variety of uses. These include making textiles, coffee filters and fishing nets. Cotton was even used in the 1890s in the manufacture of fire hoses.

A cotton boll encasing Gossypium barbadense seeds.
A cotton boll encasing the plant’s seeds.

Cotton has been used by humans for at least 7,000 years.  Archaelogists have found signs of G. barbadense domestication (based on cotton bolls found) from around 4,400 BC. It is believed that cotton spread throughout India between 2,000-1,000 BC. Following his invasion into India during 327–325 BC, the troops of Alexander the Great began to wear cotton clothes because they were more comfortable than the alternative woollen ones.

 

By the medieval period, cotton had spread to northern Europe and was imported in large quantities. It was extremely popular as it was a cheaper alternative to silk but could easily be imprinted on to make patterned textiles. At first there was a common misconception that cotton was produced by plant-borne sheep due to its woolly appearance. However, G. barbardense was soon cultivated in Europe and this misunderstanding corrected. After the introduction of inventions like the spinning jenny in the 1770s, cotton manufacture soared in Europe. The Midlands in England quickly became one of the most profitable production centres for cotton.

Image from the Leo Grindon collection. Inscription: Cotton from India: A Cotton convoy proceeding from Rewah towards to Ganges – night encampment under a Banyan tree
Image from the Leo Grindon collection.
Inscription: Cotton from India: A Cotton convoy proceeding from Rewah towards to Ganges – night encampment under a Banyan tree

From the beginning of the Industrial Revolution in Britain, textiles (particularly cotton) became their primary export. During this time, numerous inventions helped to dramatically increase cotton production. These included (but not limited to) Paul and Wyatt’s flyer-and-bobbin system for drawing cotton, Hargreaves’ spinning jenny and Crompton’s spinning mule. The invention of Whitney’s cotton gin for efficiently separating cotton fibres from the seeds reduced the time and cost of production, leading to cotton becoming one of the most widely used textile in the world. From the end of the 18th century onwards, Manchester became known as “Cottonopolis” due to its domination of the cotton trade.

Spun cotton thread
Spun cotton thread

The cotton trade continued to grow throughout the early 19th century and Britain had become one of the primary exporters. British factories imported vast quantities of fibres from India to produce cotton, but by the 1840s India could no longer supply the ever growing demand. British traders then instead turned to plantations in the United States, who quickly became one of Britain’s prominent suppliers. By the mid-19th century, cotton cultivation became one of the main occupations of slaves in the southern states of America.

 

During the American Civil War (1861-1865), the Union states blockaded the Southern ports so cotton export dwindled. This led to Britain once again needing a new source of the fibre; turning this time to Egypt. Egyptian cotton has a much higher thread count and is today viewed as a luxury brand of cotton. At the time the Egyptian government invested heavily in the trade and took large loans from European bankers to finance their fledgling cotton plantations. However, the boom in Egyptian cotton was short-lived. After the end of the America Civil War, traders abandoned Egyptian cotton in favour of the cheaper cotton supplied by the Americans. This crippled Egypt’s economy to the point that it declared bankruptcy in 1876.

 

The cotton industry in Britain reached its peak in 1912 when over 8 billion yards of cloth was produced. However, there was soon a drastic decline in trade with the onset of World War I. During the war, cotton could not easily be exported and other countries soon began developing their own industry. One such country was Japan who, by 1933, replaced Britain as the largest cotton manufacturer. The interwar period then completely destroyed Britain’s declining cotton industry. During this time over 345,000 workers became unemployed and more than 800 mills closed. Britain had become a net importer of cotton by 1958, rather than an exporter, and its remaining mills struggled to remain open. For the next few decades Britain’s cotton industry floundered and a mill closed approximately once a week. By the 1980s, Britain’s textile industry had all but disappeared.

 

The demand for cotton has doubled since the 1980s and today’s production occurs in lower-wage areas because production is cheaper. China is now the main producer of cotton, closely followed by America and India.

Cotton wool extracted from Gossypium barbadense.
A jar in the Materia Medica containing cotton wool