CHEMISTRY. 405 



while alcohol j>ives 214:.3x 40=9857.8; aBctoue gives 7523.76, chloro- 

 form 7289.5, aud carbou tetrachloride 7101; ethyl oxide 0711.8, carbon 

 disulphide 03G1.2, aud ethyl chloride G128.7 ; stannic chloride 11736.4, 

 arsenious chloride 12292.99, and ethyl acetate 12820.72; phosphorous 

 chloride 8970 5 and ethyl iodide 8938.8. The remaining two are amyl 

 alcohol, which gives 17954.04, aud bromine, 7963,2. These do not seem 

 to belong to auy of the above groups, unless the latter be placed in 

 that coutaining acetone. {Am. Journ. Sci., cxxvii, 233, in abstract by 

 G. F. B. from Berichte d. chem. Ges.) 



On the Connection between Pseudo Solution and True Solution,. hy W. 

 W. J. Nichol. — The well-known Browuian motion of small particles 

 suspended in a liquid beiug regarded as a consequence of molecular im- 

 pacts is applied by the author to support the molecular as distinguished 

 from tlie hydrate theory of solution. According to the former theory, the 

 solution of a salt in water is a consequence of the superior attraction of the 

 molecules of water for those of the salt as compared with the cohesion 

 of the salt itself. Substances are soluble in inverse proportion to their 

 cohesion. Cohesion beiug destroj^ed by subdivision, a finely divided 

 substance remains suspended for a long time in water. Such suspen- 

 sion or pseudo solution difiers only from true solution in respect to fine- 

 ness of division of the solid. If subdivision could be carried to the iso- 

 lation of the molecules, true solution would result, and substauces thus 

 dissolved could separate from solution only slowly, in spite of the supe- 

 rior cohesioH of their molecules, because aggregations of these mole- 

 cules sufficiently larger to separate themselves from solution could only 

 occasionally be found. As an instance of this we have slow precipita- 

 tion of many insoluble substauces from solution when cold and dilute. 

 (A. A. B., from Chem. News, L, 124.) 



INORGANIC. 



Liquefaction of Hydrogen. — S. Wroblewski has subjected hydrogen to a 

 pressure of 100 atmospheres in a glass tube of 2™™ external diameter and 

 of 0.2-0.4'"'" internal diameter. The tube was placed vertically', and by 

 means of a screw the compressed gas could be released instantaneously. 

 The tube and contents were cooled by boiling oxygen. At the moment 

 of releasing the hydrogen an ebullition appeared in the tube similar to 

 that observed by Cailletet in oxygen, in his experiments made in 1882. 

 The phenomenon is i)roduced in the same manner at a certain distance 

 from the bottom of the tube ; it lasts for a much shorter time and is less 

 decided and much less easy to perceive. The reason of this difficulty 

 may perhaps be explained by the very low density of liquid hydrogen. 

 Cailletet and Hautefeuille, in their researches on the density of oxygen, 

 hydrogen, and nitrogen liquefied in the ^^resence of i liquid having no 

 action on these elements, have inferred that liquid hydrogen has a den- 

 sity of 0.033. Since the same method yielded under the same conditions 



