21G ANNUAL OF SCIENTIFIC DISCOVERY. 



frost on the sides of the vessel. From trials with diflfcrcnt pro- 

 portions, he I'ouiul that tl)0 mixture of equal parts 1)}' \vci<;;ht jrave 

 the most intense cold. By mixing 1368 fjrains of tlie salt witli its 

 weight of water at 17° C. a cold of — 12° C. was ol)tained ; the 

 tt'Hipi'rature of the atmosj)hcre at tlic time of tlu; expcrinicnt was " 

 the same as tliat of the water employed. — Quarlerli/ Jounial of 

 Science, April, 1866. 



Chemical I'oisoiiiii;/. — 'M. Melsens states, in " Comptes Rendns," 

 that cidorate of potash and iodide of potassium may In; adminis- 

 tered in consideral)ie (luantitics in succession to dogs, witliout 

 injuring tliem ; wiiihs if they are given sinmltaneously, the ani- 

 mals are poisoned, apjjarently by the lormation of iodate of potash. 

 lie observes tliat tiie two salts do not react in this way under ordi- 

 nary circumstances, I)ut tiie}- do so in strong acid solutions, or 

 ■wlien in fusion, and when mixed and decomposed by the electric 

 pile. 



Orange-colored Di/e from Aniline. — Mr. Jacobsen makes red 

 aniline in the usual way l)y llie action of nitrate of mercury on 

 aniline. Tlie resitlue is then jjurilied by boiling the resinous de- 

 posit, crystallizing the solution. The motiier liijuor of the crys- 

 tals contains small (juantilics of dyes of dilVcrent colors, and a 

 large proporlic)n of orang*; ilye. Tiie orange is isolated l)y means 

 of common salt, which precipitates the other colors and leaves 

 the orange in solution. The dye is afterward extracted with 

 alcohol. The color is a golden orange, which readily dyes silk 

 and wool, and Mr. Jacobsen speaks of using it as a sort of varnish 

 for optical instriunents and on tinfoil. — Cosmos. 



Chrome Avanturine Glass. — Under this name, M. Pelouze de- 

 scribes a beautiful variety of ornamental glass, composed as 

 follows : sand, 2oU parts ; carbonate of soda, 100 parts ; carbonate 

 of lime, 50 parts ; bichromate of potassa, 40 parts. This glass 

 melts with greater dilliculty than that without the bichromate, is 

 of a deep green color, and full of small spangles, crystals of 

 oxide of chrome, wliich sparkle with a brilliancy inferior only to 

 the diamond. 



Tests for Carbolic Acid. — Carbolic acid is now largely used as 

 a disinfectant, for which it is pre-eminently fitted, especially in 

 cases of cattle disease. It app(!ars that a sj^urious article, com- 

 posed of oil of tar, utterly valueless as a disinfectant, is now 

 being imposed on the public. Mr. W. Crookes directs attention 

 to this fraud, as well as to the following means by which it may 

 be detected. Commei'cial carbolic acid is soluble in fi'om 25 to 

 70 parts of water, or in twice its bulk of a solution of caustic 

 soda, while oil often is nearly insoluble. To api^ly these tests : 



1. Put a teaspoonful of the carbolic acid in a bottle, pour on it 

 half a pint of warm water, shake the bottle at intervals for half 

 an hour, when the amount of oily residue will show the impurity. 



2. Dissolve 1 part of caustic soda in 10 parts of warm water, and 

 shake it up with 5 parts of the carbolic acid ; as before, the resi- 

 due will indicate the amount of impurity. These tests are not 

 scientifically accurate, but sufficiently so for common use. — 

 Mech. Mag., April, 1866. 



