This subject has occupied a dominant position in physico-chemical research since the investigations of van't Hoff and Arrhenius.
This is shown in the case of the chloracetic acids: According to van 't Hoff the substitution of chlorine atoms into a methyl group occasions the following increments: The introduction of chlorine, however, may involve a fall in the boiling-point, as is recorded by Henry in the case of the chlorinated acetonitriles: NC CH 3.
Van't Hoff, Lectures on Theoretical and Physical Chemistry; J.
Van Hoff pointed out that measurements of osmotic pressure confirmed this value in the case of dilute solutions of cane sugar.
This influence extended from Germany to Denmark, where it was embraced by Hoff ding, and to England, where it was accepted by Romanes, and in a more qualified manner as " a working hypothesis " by Stout.
Van't Hoff in 1885, who showed that Pfeffer's results indicated that osmotic pressure of a dilute solution conformed to the well-known laws of gas pressure, and had the same absolute value as the same number of molecules would exert as a gas filling a space equal to the value of the solvent.
The conception of a semi-permeable membrane, permeable to the solvent only, was used by van't Hoff as a means of applying the principles of thermodynamics to the theory of solution.
The physical investigation of osmotic pressure, and its correlation by Van't Hoff with the pressure of a gas, brought forward a new aspect of the phenomena, and suggested an identity of physical modus operandi as well as of numerical value.
Van't Hoff (Zeit.
Van't Hoff showed that the osmotic pressure P due to a number of dissolved molecules n in a volume V was the same as would be exerted by the same number of gas-molecules at the same temperature in the same volume, or that PV = ROn.
A formula of this type has been widely employed by van't Hoff and others to calculate heats of reaction and solution from observations of solubility and vice versa.
Van't Hoff, W.
Later followed men like Hengstenberg, Homeyer, Bethmann-Hollweg, Puchta, Stahl and Heffter; Schelling, Trendelenburg, Bopp, the brothers Grimm, Zumpt, Carl Richter; later still, Twesten and Dorner, Gneist and Hinschius; Langenbeck, Bardeleben, Virchow, Du-Bois Reymond; von Ranke, Curtius, Lipsius, Hofmann the chemist, Kiepert the geographer; Helmholtz, van't Hoff, Koch, E.
Van't Hoff and W.
An account of Raoult's life and work was given by Professor van't Hoff in a memorial lecture delivered before the London Chemical Society on the 26th of March 1902.
Van't Hoff and others have established, corresponds to the presence of one or more asymmetric atoms of carbon - that is, atoms directly united to elements or radicles all different from one another - and in every case there exists an isomer that rotates the plane of polarization to the same degree in the opposite direction.
Van't Hoff and Le Bel, occupies such a position in organic chemistry that its value can never be transcended.