Biographies

Although he never perfected his product, Alexander Parkes (1813-1890) invented one of the earliest forms of plastic. It eventually led to the commercial and manufacturing success of plastic products. A talented metallurgist and inventor, Parkes held 66 patents on processes and products related to electroplating and plastic development.

The son of a brass lock manufacturer, Parkes was born on December 29, 1831, in Birmingham, England. He apprenticed to a brass founder at Messenger and Sons before going to work at Elkingtons, the company that invented the electroplating process, which used electricity to deposit a layer of metal. Parkes was put in charge of the casting department, and his attention soon began to focus on electroplating, a recently discovered process.

Parkes took out his first patent (No. 8005) in 1841 on a process for electroplating delicate works of art. His improved method for electroplating fine and fragile objects, such as flowers, was granted a patent in 1843 (No. 9807). Parkes first dipped the object to be electroplated in a solution of phosphorus contained in bisulfide of carbon, and then placed it in nitrate of silver. Once covered with the nitrate of silver, the object was placed in yet another solution, which was connected to a battery. The result was a process by which a layer of copper, silver, or gold could be deposited on the object in varying amounts. When Prince Albert visited Elkingtons, Parkes presented him with a spider's web coated with a layer of silver. So attentive to the skill of his work was Parkes that on his early patent applications he identified himself as an artist. Only later did he adopt the title of chemist.

Perfected Desilverisation and Waterproofing

Parkes's most important development related to metallurgy came during the three years he spent as the superintendent of the construction of an Elkington and Mason copper smelting plant in Pembrey, South Wales. He invented a process by which silver is extracted from lead by using molten zinc, a method that became known as the Parkes process. His desilverisation process was first patented in 1850 (No. 13118), with further developments receiving patents in 1851 (No. 13673) and 1852 (No. 13997). The Parkes process gained considerable attention in Germany and was widely used in the United States for some time.

His next project was an improved method for printing calico. To this end, he developed and manufactured seamless metal tubes and cylinders, again receiving numerous patents on his inventions.

Although Parkes was a prolific inventor and was awarded 66 patents during a period of 46 years, most of which related to metallurgy, he also contributed to advancements in other areas. In 1846 he was granted a patent for the invention of a cold vulcanization process. Used extensively by Goodyear in the United States and Hancock in England, it was a means by which materials could be rubberized with a cold solution, replacing the need for natural rubber to be treated in sulfur at high temperatures. Using his vulcanization process, material such as cloth could be rubberized by using a solution of rubber in bisulfide of carbon, which produced a thin, waterproof article. Elkington and Mason used the process for waterproofing before selling the patent rights to Macintosh and Company, who became famous for their waterproofing products.

Discovered Parkesine

Parkes is best remembered for his invention of what would later be developed into plastics. He was not the first to develop a plastic substance, but before his work plastics were primarily curiosities created and displayed in scientific laboratories. Cellulose nitrate, the basic substance of Parkes's creation, was itself a new invention. Henri Bracconet, the director of the Botanical Gardens in Nancy, France, was the first to prepare it in 1833, by mixing sawdust cellulose with nitric acid. In 1855 Christian Schonbein, a professor at Basle University, imitated Bracconet's method by treating simple paper made from wood cellulose with nitrite acid. The result was a transparent, highly flammable substance, which Schonbein named cellulose nitrate and marketed as an explosive.

Soon it was discovered that cellulose nitrate, when mixed with ether and alcohol, became soluble. Because it shrank as it dried, the solution, which became known as collodion, was marketed for use in medicine to seal minor wounds. Other ideas for marketing forms of collodion were explored. In 1851 F. Scott Archer placed a thin layer of collodion on a sheet of glass. When the collodion dried, it could be peeled from the glass. The sheet was transparent and could hold an image. It was thus the precursor to modern film. Also, dye was added to collodion, which was then sold as finger nail polish.

Parkes began to experiment with the creation of a substance that could replace ivory, which was getting rarer because it could only be obtained from an expensive and dwindling supply of elephant tusks. He noted the behavior of an old jar of collodion in his medicine cabinet. When exposed to air for an extended period of time, it turned into a moldable form. Working from the basic concept of collodion, Parkes experimented with a new substance. It was at first called xylonite or parkesine and later celluloid. According to Sylvia Katz in Plastics: Designs and Materials, "[Parkes] took cellulose nitrate in the form of cotton fibre or wood flour dissolved in nitric and sulfuric acids, and mixed it with vegetable oils such as castor oil and wood naphtha. The combination made a dough which could simulate ivory and horn, and could be textured and painted. He fully realized the potential of his discovery and first exhibited a few moulded household goods -- knife handles, combs, plaques, and medallions -- at the 1862 International Exhibition in London, where they aroused sufficient interest for him to receive a bronze medal." Parkes also received recognition in 1867 at a similar exhibition in Paris.

Parkesine was softened by heat and then placed in molds or carved by hand. It could also be painted or inlaid with ornamentation. Much less expensive than its counterparts in leather or rubber, the product had more potential for economic success. Parkes created a list of all the devices he believed could be replaced by products made of parkesine. These included brush backs, shoe soles, whips, walking sticks, buttons, brooches, buckles, decorative work with inlay and piercings, tubes, umbrellas, treated cloth, counters, and balls, (especially billiard balls, which at the time were made of ivory). Parkes also added dye to parkesine and created mottled effects by mixing different batches of red, yellow, green, and orange parkesine, resulting in a brightly colored product. Some of Parkes's early productions using parkesine are displayed at the Plastics and Rubber Institute in London. More than a century after their creation, the colors remained brilliant.

Business Began and Ended

Using Parkes's process, the cost of producing cellulose nitrate was reduced from 12 shillings to seven pence a pound, a considerable savings that pointed to its commercial value. As a result, Parkes took out numerous patents on parkesine between 1855 and 1865. In 1866 he founded the Parkesine Company and began the commercial production of his new product. However, his attempts at financial success failed. In Plastics History U.S.A., J. Harry DuBois wrote: "the Parkesine Company operated haltingly till 1868, [Parkes'] failure to succeed commercially being attributed, in part, to an overconcern for low costs, leading to the use of poor quality raw materials. Since Parkes lived more by developing processes than by operating them on a commercial basis, it is perhaps not surprising that this venture into production was unsuccessful."

Parkes enlisted the help of an established businessman, Daniel Spill. A talented chemist, Spill had been awarded a medal for his waterproofing product in 1862 at the Great Exhibition in London. His interest in waterproofing first drew him to Parkes, and in 1866 he became the works manager at the Parkesine Company. When Parkes decided to discontinue his commercial attempts, Spill took over the company. He renamed it the Xylonite Company and began to market celluloid as Xylonite and Ivoride. He also had problems with production and went bankrupt in 1874. Spill reopened in a new location the following year, and in 1877 took on several partners, becoming the British Xylonite Company, which achieved commercial success producing celluloid collars and cuffs.

Celluloid could be molded easily at low temperatures and cured at room temperature. This meant that no expensive machinery was needed to form the product at extreme temperatures or under high pressure. The key problem with celluloid was its combustible nature because it contained nitrate. Any products formed from celluloid were highly flammable, so celluloid products eventually were banned from production, including men's collars and play dolls.

In addition, the parkesine developed by Parkes was an extremely hard plastic, more ceramic or bone-like in consistency. A short time after Parkes quit his business, John Wesley Hyatt of the Hyatt Brothers in the United States discovered that nitrate cellulose mixed with camphor created a much more pliable product. It would be the Hyatt Brothers who would make advancements in Parkes's invention and market it with worldwide success, ushering in the age of modern plastics. Parkes, who never achieved commercial success with his precursor to plastic, retired to London and died at West Dulwich on June 29, 1890.

Further Reading

• A Biographical Dictionary of Scientists, edited by Trevor I. Williams, Halsted Press, 1974.
• A Biographical Encyclopedia of Scientists, edited by John Daintith, Sarah Mitchell, and Elizabeth Tootill, Facts on File, 1981.
• The Cambridge Biographical Encyclopedia, 2nd edition, edited by David Crystal, Cambridge University Press, 1998.
• The Dictionary of National Biography, edited by Leslie Stephen and Sidney Lee, Oxford University Press, 1973.
• Dubois, J. Harry, Plastics History U.S.A., Cahners Books, 1972.
• Katz, Sylvia, Plastics: Designs and Materials, Cassell and Collier Macmillan, 1978.
• "Alexander Parkes," Merriam-Webster's Biographical Dictionary, http://www.galenet.com (February 10, 2001).
• "Alexander Parkes," World of Invention, http://www.galenet.com (February 10, 2001).