powder. Girard explains in this way the brittleness of certain pa- 

 pers bleached with chloride of lime. — C. B., Ixxxi, 1105, Dec. 1875. 



2. On the Decomposition of Stearic Acid by distillation under 

 Pressure. — Under the direction of Professor Thorpe, Johjtston has 

 submitted stearic acid to distillation under pressure, with a view to 

 determine the decomposition products. A copper tube was em- 

 ployed for this purpose, bent twice at right angles. At the second 

 bend from the end, which served as the retort, was an elongation 

 of the tube serving as a receiver. The end of the tube was provided 

 with a stopcock to allow the gases to escape. The stearic acid was 

 heated, allowed to distill over, then run back into the retort, again 

 distilled over, and so on until the acid was completely decomposed. 

 The liquid products were collected and examined. They proved 

 to be hydrocarbons of the marsh gas and olefine series exclusively. 

 The gases resulting were similar, with the addition of water va- 

 por and carbon dioxide. — J. Chem. Soc, II, xiv, 8, Jan., 18*76. 



3. On Liquid Carbon Dioxide in mineral cavities. — On 

 heating a microscopic slide of quartz containing fluid cavities 

 only to a moderate temperature, Hartley was surprised to find 

 that the liquid, previously perfectly visible under the microscope, 

 had disappeared. On cooling, the liquid reappeared accompanied 

 by a sort of flickering movement within the cavity. Experiments 

 on fluid cavities in various minerals made by Brewster in 1823, 

 showed that the liquids all disappeared below 88° F., that their 

 expansion between 50° and 80° F. was 32 times that of water, and 

 their index of refraction 1-2946 in topaz and 1-2 106 in amethyst. 

 From these results Simmler, and later, Sorby and Butler con- 

 cluded that the liquid must be carbon dioxide. The author 

 sought carefully to determine the critical point of the liquid, 

 which he did by immersing the slide in water of known tempera- 

 ture, removing, wiping hastily, and examining. As a result, it 

 appeared that the critical point lay between 30-75° and 31° C, 

 that point for pure carbon dioxide having been fixed by Andrews 

 at 30-92° C. In further corroboration of this view is the fact that 

 when water was also present in the same cavity, the other liquid 

 floated on it ; the density of carbon dioxide being 0-83 at 0° and 

 0-6 at 30°. Moreover, Geissler has shown the presence of this gas 

 in quartz by its spectrum in a vacuum tube in whicli the quart^ 

 was broken. In explanation of the formation of these fluid cavi- 

 ties, the author supposes the silica in hot solution to iiave come in 

 contact with a limestone under pressure, setting free carbon diox- 

 ide which being enclosed in the crystal cavities along with water 

 would on cooling condense to a liquid. — J. Chem. Soc, xxix, 13/, 

 February, 1876. *^; ^;. f • 



4. Deconqyosition of Alcohol by Aluminum and its Iodide.— 

 Gladstone and Tribe have continued their researches on the ac- 

 tion of aluminum in presence of its haloid salts upon organic 



