108 



The extraordinary discrepancy between theory and experiment 

 may be removed in two ways : viz. either by halving the formula, 

 or by assuming that the molecule of the dioxide of ethylene-diethyl- 

 diammonium corresponds to 8 volumes of vapour, in either of which 

 cases the theoretical density becomes 2'31, closely agreeing with the 

 experimental number 2 '26. 



I shall discuss the vapour-densities of the diammonias somewhat 

 more fully in a future communication ; but I cannot refrain from 

 pointing out even now, that, by dividing the formula by 2, we arrive 

 at an expression containing 1 equiv. of oxygen (O=8), which, in the 

 eyes of those who consider the number 16 as the true molecular 

 value of oxygen, must appear perfectly inadmissible. 



IV. " On the Behaviour of the Aldehydes with Acids." By 

 A. GEUTHER, Esq., and R. CARTMELL, Esq. Communi- 

 cated by Dr. FRANKLAND. Received June 8th, 1859. 



[Abstract.] 



The authors of this paper, with a view of obtaining a series of 

 combinations homologous with those already obtained from glycol by 



Wurz viz. diacetate of glycol, C 4 H 3 O 2 } O 4 , and the isomeric body 



q.H.o. 



of Geuther from common aldehyde, by the action of anhydrous 

 acetic acid, have subjected common aldehyde, acrolein, and oil of 

 bitter almonds to the action of hydrochloric, hydriodic, and sul- 



phurous acids. 



I. Acrolein, Metacrolein. 



1 . Acrolein and Hydrochloric Acid. 



By acting on acrolein, C 6 H 4 O 2 , with dry hydrochloric acid gas, 

 a body is formed of the composition C 6 H. O 2 Cl, resulting from a 

 direct combination of one atom of aldehyde with one atom of the 

 acid. This substance is insoluble in water, and can be washed with 

 it in order to free it from any excess of acid or acrolein which may 

 be still present. By drying, which can only be done over sulphuric 

 acid at low temperatures, the body, for which the authors propose 

 the name of hydrochlorate of acrolein, is obtained in a mass of 

 white crystals, presenting a texture like that of velvet. It melts at 

 32 C. into a thick oil, having a smell of slightly rancid fat. It is 



