CHEMISTRY. 231 



Deiermination of Silver. — The method of Gay Lussac for the 

 determination of silver by titration as chloride is subject to a 

 sliglit error, on account of the sokibilit}' of the chloride of silver in 

 the liquid from which it is precipitated. Stas proposes to deter- 

 mine the silver as bromide, and thus avoid this error. — Compt. 

 Rend. 



New Test for Wool. — Wagner dissolves a decigramme of the 

 material to be analyzed by boiling it in 10 to 15 c. c. of a strong 

 solution of potash, dilutes to 100 c. c, and then tests this solution 

 with nitro-prusside of potassium. The presence of the smallest 

 quantity of wool causes a violet coloration of the liquid — Mon. 

 Sci. d. Quesn. 



Action of Heat on Tartaric Acid. — Dr. Sace has observed that, 

 when tartaric acid is heated in a glass retort, acetic acid distils 

 over ; there is left in the retort a carbonaceous mass, while car- 

 bonic acid escapes. 



Oxidation of Acetic Acid into Oxalic Acid. — When one part of 

 acetate of sodium, one part hydrate of sodium, and two parts of 

 permanganate of potassium are dissolved in a little water, the 

 solution concentrated by boiling, finally evaporated to dry- 

 ness, and the residue heated until it ceases to give with water a 

 green colored solution, oxalic acid is found to exist in the saline 

 mass. 



Action of Cyanogen on Hydrocliloric Acid. — When a current of 

 gaseous cyanogen is passed into hydrochloric acid as concen- 

 trated as possible, no coloration is observed, but after twelve 

 hours crystals of oxamide make their appearance, and the super- 

 natant liquid contains oxalate of ammonium. With hydriodic 

 acid the result is the same ; oxamide is likewise formed, but 

 iodine is displaced, and the liquid is found to contain hydrocy- 

 anic acid and iodide of ammonium. — Engineer. 



Horse-cliestnut leaves, according to Rochleder, contain a tannin 

 which is found also in the tormentilla root ; in the former it is 

 converted into aescigenin, C24 H20 O4, in the latter into kinovic 

 acid. — Chcm. Centralb. 



Discovery of a New Base. — M. Wurtz has succeedt;d in obtain- 

 ing a new base by making chlorhydratc of glycol act upon tolui- 

 dine at a temperature of from 200° to 220° C. This substance 

 exhibits a beautifully green liuorescence, has a bitter taste, and is 

 precipitated by iodine in solution of iodide of potassium. It con- 

 tains two atoms of hydrogen less than toluidine, while for two 

 other hydrogen atoms are substituted a vinyl and an hydroxethy- 

 len group. The chloroplatinate of the base is a crystalline sub- 

 stance readily decomposed by heat. — Bull. Soc. Ch.^ Nov. 4, 

 1869. 



