Thomas graham chemistry biography books

It has since been justified by the condensation of hydrogen gas by means of pressure and cold into a bluish solid having a metallic ring. Graham even laid down the bold theory that all the so-called elements may be only forms of one primordial element. Among his minor chemical researches were his experiments showing that the slow oxidation of phosphorus by air is arrested by the presence of even mere traces of olefiant gas, and that the spontaneous inflammability of phosphuretted hydrogen is due to the presence of a small proportion of nitrous acid.

Graham will be especially remembered for his discovery of the law of the diffusion of gases, which he showed to be inversely proportional to the square roots of their densities. He also studied the manner in which liquids permeate membranes dialysisand named those substances which had a high diffusibility crystalloids, and substances of a low diffusibility colloids; this research has an important bearing upon the phenomena of osmosis, and explains many facts connected with animal and vegetable life.

The striking features of Graham's work are its originality and the simplicity of his methods, leading nevertheless to important and indeed fundamental results. In his later work Graham was ably assisted by Mr. Roberts-Austen, the present head of the Mint. A bronze statue of Graham was placed in George Square, Glasgow, in James Young, and printed privately inthe volume having a preface by Dr.

Page Source Discussion. Read Edit View history. Tools Tools. Wikimedia Commons Wikisource Wikidata item. British chemist — GlasgowScotland. Graham's law Dialysis. Royal MedalCopley Medal Anderson's Institution University College London. Life [ edit ]. Publications [ edit ]. Scientific works [ edit ]. This section needs expansion with: further information, based on verifiable sources, elaborating on Graham's laws, and extending the information on Graham's contributions.

You can help by adding to it. July Honours, activities, and recognition [ edit ]. See also [ edit ]. References [ edit ]. Retrieved 24 December Oxford Dictionary of National Biography online ed. Oxford University Press. Retrieved 25 November He concluded that the rate of effusion or diffusion of a gas at a constant temperature is simply inversely proportional to square-root of its density.

InGraham examined liquids. He noted that colored sugar solution placed at the bottom most part of a glass of water gradually extends its color upward. This process was called diffusion. He also noted substances like gelatin, glue, albumen and starch diffuse slowly. He classified substances into two types: crystalloids, substances that diffuse quickly, and colloids, substances that diffuse slowly.

Other works by Thomas Graham includes research into phosphorous acids, absorption of hydrogen by palladium and the water of thomas graham chemistry biography books in hydrated salts. As a lecturer Graham was well liked by his students, but he was somewhat nervous and hesitant. He was much in demand as a consultant. Most of his work lay in the field of inorganic and physical chemistryand he is recognized as the real founder of colloid chemistry.

His work, usually quantitatively accurate, was original in conception, simple in execution, and brilliant in the results to which it led. Much of his earlier experimental work, some of it not very accurate, is said to have been performed by students and assistants. His original and admirable textbook Elements of Chemistry was widely used, not only in England but also on the Continent, in its much enlarged multivolume translation by Friedrich Julius Otto.

In another work he found that, like potash, ammonia forms a normal oxalate, binoxalate, and quadroxalate, but that soda forms only a normal oxalate and binoxalate. He also made interesting observations on the glow of phosphorous and the spontaneous flammability of phosphine. In Graham published the first of his papers relating specifically to the subject of gaseous diffusion.

The diffusion or spontaneous intermixture of two gases in contact is effected by an interchange in position of indefinitely minute volumes of the gases, which volumes are not necessarily of equal magnitude, being, in the case of each gas, inversely proportional to the square root of the density of that gas Graham maintained that by means of this law the specific gravity of gases could be determined, through experiments on the principle of diffusion, with greater accuracy than by ordinary means.

He also pointed out that mixtures of gases could be separated by diffusion, a process employed during World War II at Oak Ridge, Tennessee, to separate the fissionable isotope uranium from the nonfissionable isotope uranium Graham also measured the effusion of gases through a small hole in a metal plate and found the velocities of flow to be inversely proportional to the square roots of the densities.

Yet in his study of the rates of transpiration of gases through capillary tubes, he found that the rates became constant with a certain length of tube and were not simply related to the densities. He later supposed hydrogen to be the vapor of a very volatile metal, hydrogenium, which forms an alloy with the metal.

Thomas graham chemistry biography books

Compounds of one and the same anhydrous acid with one and the same anhydrous base, in different proportions, had long been known, but Graham was the first to establish the concept of polybasic compounds, that is, a class of hydrated acids with more than one proportion of water replaceable by a basic metallic oxide so that several series of salts could be formed.

Graham concluded that the individual properties of the phosphoric acids could not be expressed if they were regarded as anhydrides; they must contain chemically combined water essential to their composition. He therefore designated the three modifications of phosphoric acid as phosphoric acid, that is, 3HO. PO 5 modern, 3H 2 O. P 2 O 5 or H 3 PO 4 ; pyrophosphoric acid, i.

PO 5 modern, 2H 2 O. P 2 O 5 or H 4 P 2 O 7 ; and metaphosphoric acid, i. PO 5 or modern, H 2 O. In other words, he regarded them respectively as a triphosphate, a biphosphate, and a phosphate of water. When one of these compounds is treated with a strong base, the whole or a part of the water is supplanted, but the amount of base in combination with the acid remains unaltered.

Graham summarized the compositions of the three acids of phosphorus and of their sodium salts as shown below. Just as in his demonstration of the relationships to one another of phosphoric acid and the three sodium phosphates, Graham originated the concept of polybasic compounds; so, in his demonstration that the pyrophosphates and metaphosphates are compounds differing from the phosphates by loss of water or metallic base, he originated the concept of anhydro compounds.