Williams, Greville

Historically the phenazine dyes have played an important part in the dyestuffs industry, although their use has largely been superseded by the more modern, color-fast dyes, in particular those dyes which become chemically bonded to the fibers of the materials being dyed. Amongst the earliest examples of phenazine dyes are those compounds known as the safranines. The discovery of the safranines has been attributed to Greville Williams in 1859 and they were apparently in commercial use shortly after that date, but it was not until 1886 that it was recognized that phenosafranine (138) was indeed a phenazine containing system. 

The first cyanine dye was made in 1856 by Greville Williams. Thus the blue charge-resonance system 6.216 was produced when oxidative coupling took place between N-... 

It was well known at the turn of the century that rubber has the empirical composition, C5H9. Michael Faraday elucidated its composition in 1826 by careful elementary analysis. His work, an effort of extreme complexity, has been diminished by the years, but it regains its stature when you recall that over thirty years passed before the next major step was performed. In those thirty years rubber was blended, dissolved, and even vulcanized (by Charles Goodyear in 1839), but it was in 1860 that its major chemical component was discovered. This important finding was made by Greville Williams. He named the product of the destructive distillation of rubber, isoprene. 

Synthetic rubbers include a variety of compounds that mimic the properties of natural rubber. In 1860, Charles Greville Williams (1829-1910) isolated the monomer isoprene from rubber, showing that rubber was a polymer of isoprene ... 

After Bunsen had detected and isolated caesium, spectroscopy was taken up with great enthusiasm by William Crookes, and this led to his detection and isolation of thallium in 1861.191 Crookes letters to Charles Hanson Greville Williams, who was also working with the spectroscope, and who felt he deserved some of the credit for the discovery of thallium, have been published.192 The use of spectrochemistry in the search for hitherto unknown chemical elements in Britain over the period 1860-1869 has been described. It was perceived that, like Crookes, a scientist could make his reputation by discovering a new element. This resulted in several claims for the existence of new elements that later proved to be unfounded.193 Once Kirchhoff had established beyond doubt that the dark Fraunhofer lines were caused by the same element that caused emission lines of identical wavelengths, the way was open for the chemical analysis of the atmosphere of the sun and stars. This was a process which had been declared to be an impossibility by Auguste Comte less than 30 years previously.194... 

Isoamylcyanine, discovered by Greville Williams [5] and examined later by Hofmann [2], is best known. According to Hofmann it is formed from pure lepidine and possesses the composition C30H39N2I. In all these iodides the iodine may be replaced by other acid radicals. 

It is possible that the cyanines are constituted similarly to the phenylmethane dyestuffs, the methyl group of the lepidine furnishing the methane carbon atom. The cyanines belong to the earliest artificial dyestuffs, the first representative having been discovered by Greville Williams in 1856. 

For nearly sixty years chemists of all countries have devoted much time and labour to its synthetic production in the laboratory. In 1860 Greville Williams isolated a compound, which he called isoprene, from tho products of the distillation of... 

Crude rubber is primarily hydrocarbon in nature. In 1826 English chemist Michael Earaday (1791-1867) analyzed natural rubber and found it to have the empirical (simplest) formula C5H8, along with 2 to 4 percent protein and 1 to 4 percent acetone-soluble materials (resins, fatty acids, and sterols). In 1860 English chemist Charles Hanson Greville Williams (1829-1910) confirmed Earaday s analysis and in 1862 distilled natural rubber to obtain the pure monomer, which he named isoprene. He determined isoprene s vapor density and molecular formula, and he showed that it polymerizes to a rubbery product—an observation that led to the notion that rubber is a linear polymer of isoprene, proposed in 1910 by English chemist Samuel Shrowder Pickles (1878-1962). 

C. Greville Williams, lecturer in the Normal College, Swansea, separated a number of hydrocarbons and determined their vapour densities. He found that they differed in composition by multiples of C2H4 and regarded them as free radicals. ... 

The history of the use and study (it occurred, as in so many other cases, in that order) of rubber goes way back. Pietro Martyre d Anghiera described it in 1511. In 1839, Charles Goodyear found that sulfur could vulcanize rubber, thus its usefulness was greatly expanded. Still rubber, except for Faraday s report on its empirical composition, was an unknown, until Greville Williams destructively distilled the material in 1860 and identified the distillate as isoprene. 

Long before the structure of rubber had been established attempts to prepare a synthetic rubber had been made. In 1860 Greville Williams distilled rubber and then fractionated the distillate. From the lowest fraction Williams obtained a liquid boiling at 37-38 C which he called... 

Kekule s theory is unnecessary and introduces mystical considerations. The theory of relative saturation was applied to the camphene series, based on a hydrocarbon C H (—)(—), either identical with the isoprene of C. Greville Williams, or isomeric with it. Camphene and its isomers Berthelot represented by the formula C H (C H )[—][— ][—]. His ideas had no influence on the development of chemistry. 

The compositional details of caoutchouc, gutta-percha (an isomer of caoutchouc) and caoutchoucine were finally settled by Charles Greville Williams (1829-1910) [10]. In 1860 he carried out a substantially more careful dry distillation of caoutchouc in an iron alembic and isolated two volatile fractions. The lower boiling one (37-38 °C) had a (modem) molecular formula of CsHg, not just an empirical formula. He called it isoprene, to distinguish it from the cmde fractions obtained by previous workers. A dimer was also isolated and characterized. All these materials had the same pure hydrocarbon empirical formula. 

---