OF ARTS AND SCIENCES. 213 



0.5679 <rr. of substance gave, after ignition, with CaO 0.8579 gr. 



AgBr. 



Required for C-HgBr^. Found. 



Carbon 33.6 33.90 



Hydrogen 2.4 2.57 



Bi'omine 64.0 64.28 



100.0 100.75 



Properties. — Crystallized from alcohol, it forms thick, colorless nee- 

 dles, with a brilliant lustre ; from the oily mother-liquor formed in its 

 preparation or from benzole, it sejiarates on slow evaporation in well- 

 formed prisms, apparently of the orthorhombic system, often a centime- 

 ter or more long and two to four millimeters thick, which have the 

 consistency of sublimed sal-ammoniac. Its odor is agreeable and 

 aromatic, but its vapor attacks the mucous membrane with very great 

 violence, causing tears and running at the nose ; it was observed, how- 

 ever, by all who were exposed continually to its action that they 

 became much less sensitive to it after a few days. "When brought upon 

 the more delicate parts of the skin, it causes a sharp, stinging pain, but 

 produces no such effect on the hands ; the taste is extremely biting, 

 causing great pain to the tongue for several minutes ; it melts at 61-^°, 

 can be distilled with steam, sublimes in laeedles, and burns with a lumi- 

 nous green-bordered flame. It is almost insoluble in water, although 

 it imparts its odor to it; (the flat needles, mentioned in a preliminary 

 paper* as separating from water by spontaneous evaporation, were 

 undoubtedly the more soluble parabrombenzylalcohol) ; it is but slightly 

 soluble in cold, freely in hot alcohol, very readily in ether, benzole, 

 carbonic disulphide, and glacial acetic acid. On one occasion, it was 

 oxidized very rapidly by a mixture of potassic dichromate and dilute 

 sulphuric acid, the action being attended by flashes of light visible even 

 in diffused daylight, the product was an acid melting in the crude state 

 at 239" to 240^*, which must therefore be parabrombenzoic acid. 



It seems highly probable that this parabrombenzylbromide is the 

 substance obtained, but not purified or studied by Lauth and Grimaux,t 

 in 1866, in the residue from the distillation of bromtoluol ; since they 

 described it as crystallizing in needles, and in the highest degree irritat- 

 ing to the eyes. 



* Ber. D. Ch. G., 1876, p. 931. 



t Lauth and Grimaux, Bull. Soc. Chim. [2], V. p. 347. 



