412 Scieiitific Intelligence. 



the author experimented on the specific heat of potassium, and he found 

 it to be 5*40 in his best trial, a result which sustains his conclusion. He 

 hence infers that the equivalent of potassium should be halved, and 

 that the formula of the alkaline oxyds is R 2 O. 



7. On Chloroniceic Acid; by M. E. Saint Evre, (Ann. de Chim. et 

 de Phys., April, 1849.) — This acid is obtained by the action of chlo- ! 



rine upon benzoic acid in the presence of an excess of alkali. 



Two hundred parts hydrate potash and 60 benzoic acid are dissolved 

 in 300 water — chlorine is passed until the liquid changes yellow and 

 finally green, with a pulpy deposit. By saturating the excess of potash 

 and boiling, this deposit is dissolved and an oily liquid appears, which 

 floats or sinks, according to the density of the solution, and on cooling, 

 concretes and becomes hard and brittle. Repeated crystallizations 

 first from water and finally from alcohol afford the pure acid. 



Chloroniceic acid forms microscopic crystals, which are four-sided 

 prisms; it is volatile without decomposition, the odor is penetrating and 

 resembles that, of most chlorinated compounds, being quite different 

 from that of benzoic acid. Distillation with lime or baryta produces a 

 liquid and a solid hydro-carbon ; other powerful reagents seem to have 

 no effect. 



The formula of the author is C 12 H 5 CI 4 . Salts of baryta, silver, 

 &c, were formed. 



[The formula above given is that of a chlorinated species of white 

 hydro-quinone, (Pyroquinol, Ger.) C 12 H 6 4 , one equiv. of hydrogen , 



being replaced by one of chlorine. That this is the true relation of 

 the so-called chloro-niceic acid, is not surprising, when we remember 

 that VVohler found benzoic acid and bodies allied to it among the pro- 

 ducts of the destructive distillation of quinic acid. Benzoic acid more- 

 over differs from hydro-quinone, only by two equiv. of carbon. In the 

 process detailed above, there is oxydation and substitution of chlorine 

 simultaneously carried on. It is true that Hoffman failed to obtain 

 chloranile from benzoic acid by chromate of potash and muriatic acid; 

 but from the reaction above mentioned, it would appear that the product 

 should have been a quadri-chloro-hydro-quinone, which is in reality 

 colorless and might well have been overlooked. 



But we have more conclusive evidence of the correctness of our 

 opinion in the researches of Dr. Staedeler, (more particularly no- 

 ticed below,) in which he has proved the existence of several chlo- 

 rinized species of hydro-quinone — in fact of all but this very one 

 which he does not seem to have formed ; his process, however, was 

 a totally different one. As it is, the description of the others will 

 answer almost word for word for this, which should be called mono* 

 chloro- hydro-quinone, a name somewhat longer than that given by the 

 discoverer, but which has the advantage of expressing at once the re- 

 lation to twelve different allied bodies. G. C. Schaeffer. 



8. On the Chlorinated Products of the Decomposition of Quinic Acid ; 

 by Dr. G. Staedeler, (Liebig's Ann., March, 1849.) — It is well known 

 to chemists that by distilling quinic acid with sulphuric acid and per- 

 oxyd of manganese, a substance called quinone, C 12 H 4 4 , is formed, 

 which is very singular in its properties and reactions. Under the influ- 

 ence of an excess of reducing agents, e. g., sulphurous acid — two equiv. 



