} 



Chemistri/ and Physics. 263 



Aceto-benzolic etlier is prepared by tlie action of chlorbenzol upon ace- 

 tate of silver. It forms colorless crystals which have the formula 



(0^11^02)2 r ^** '^^^ action of aqueous ammonia upon aceto-Lenzolic 



iither yields acetamid and hydrobenznmid. The author sua'gests that hy- 



C14II6 

 drobenzamid is tribenzolamiuj C42His]S'2r=IS'a \ CuHe, and that stilben 



, C14H6 



may be the radical benzol, CasHis^Hp ^^ t , and benzoin benzolic ether, 



C28Hi204:^p jy v 04. — Ann, der Chemie und Pharmacie^ ci, 291. 



\Note, — -As there are few substances in organic chemistry more inter- 

 esting or more important than the oil of bitter almonds, it appears desir- 

 able to have a single word for it in j)lace of its present inconvenient ap- 

 pellation. I suggest the name picramol as appropriate and convenient. 



W. G.] 



2. On the action of light upon chlorid of silver, — Guthrie has insti- 

 tuted a few experiments which tend to show that the blackening of chlo- 

 rid of silver by light, as supposed by Scheele, is due to the libejation of 

 chlorine and the deposition of metallic silver. "WTien dry chlorid of silver 

 was exposed to light in a sealed tube, chlorine was found to be present in 



I a free state. The blackening took place in benzol boiled so as to expel 



air. Tlie gray mass of altered chlorid was heated with ammonia, which 

 left a slaty grey substance which took the metallic lustre under a pestle, 

 snd was soluble in nitric acid and precipitated by chlorhydric acid, but 

 not by ammonia. In another experiment the quantity of silver reduced 

 and the quantity of chlorine set free were both weighed as chlorid of sil- 

 ver, and the weight found to agree as nearly as could be expected, also the 

 quantity of chlorid of silver yielded by the metallic silver reduced agreed 

 with the theoretical quantity. The blackening took place under nitric 

 acid concentrated or dilute, and the quantity of chlorid found by the 

 black matter agreed nearly with the amount of chlorid which should be 

 yielded by pure silxer.— Quarterhj Journal of the Chemical Society^ x, 74. 



3. On the use of the prisjn in qualitative analysis. — Gladstone has 

 studied the colore of various salts by means of the prism, and has made 

 ,an interesting and valuable contribution to a branch of physico-chemistry 

 heretofore too much neglected. The author employed in the analysis of 

 liquids a wedge-shaped glass vessel, so placed that the line of light from 

 the window traversed diiferent thicknesses of the hquid and was then 

 analyzed by means of a prism. The appearances as thus seen are easily 

 transferred to paper, a^ Fraunhofer's lines are under favorable circumstan- 

 ces distinctly visible. As a general result, the author states that all the 

 compounds of a particular base or acid have the same effect on the rays 

 of hght. Exceptions to this law occur, though jery rarely. As it would 

 ^oi be possible to understand the author's special results without the aid 

 of figures, and as our limits will not permit us to give all his details, we 

 shall content ourselves with a sketch of the characters of the salts of a 

 few metals. The difference in color between certain chromium salts van- 

 ishes entirely when the solutions are examined in the manner pointed out. 



