in 



Chemistry and Physics. 267 



facility, and are not volatile without decomposition. They also resem- 

 ble each other in having no deleterious action upon the animal system, 

 a property that is very remarkable in a body which like alcargene con- 

 tains more than 72 per cent, of arsenic. From these facts the conclu- 

 sion seems unavoidable, that alcargene is the arsenical species of a 

 genus of which glycocoll may be regarded as the type. 



Glycocoll is isomeric with the hyponitrous ether of Liebig. This 

 substance which is regarded by M. Gerhardt as the nitric species of 

 acetene C 4 H 6 , is, like many other bodies of a similar constitution, de- 

 composed by the action of sulphuretted hydrogen. When a current of 

 this gas is passed into an alcoholic solution of the ether, previously 

 mixed with a little solution of ammonia, it is rapidly absorbed, while 

 the liquid assumes a dark orange-red color, and deposits a large amount 

 of sulphur. In this process a volatile substance of a powerful alliaceous 

 odor and pungent taste is formed, but the small quantity which I obtained 



a single experiment, did not allow me to determine its nature. It 

 may perhaps be a body corresponding to alcarsine, of the formula 

 8" 12 N 2 2 , or a sulphuretted species of it. Four equivalents of the 

 ether, and eight of the sulphuretted hydrogen, would yield one equiva- 

 lent of this compound with the separation of six equivalents of water 

 and eight of sulphur ; the tendency of the bodies of the acetic series to 

 unite and double their equivalent, is well known. This however is 

 merely a probable conjecture, and I shall take the earliest opportunity 

 to determine its truth or falsity. The substance C 8 H l2 N 2 2 should 

 yield glycocoll by oxydizing agents. 



« will be very important to examine the action of reducing agents 

 a Qd sulphuretted hydrogen upon glycocoll, as alcargene, by these means, 

 attords alcarsine, and a species in which its oxygen is replaced by sul- 

 phur. I have commenced some researches upon these, the results of 

 hich I will send you as soon as they are completed. 



Montreal, May 25ih, 1847. 



3 - Varrenlrapp and WilVs Method for the Determination of Nitro ■ 

 g e *: An Improved Apparatus; by Prof. E. N. Horsford, (commu- 

 nicated for this Journal.)— The excellence of the method of MM. Var- 

 renlra PP and Will, in the combustion of bodies whose per-centage of 

 mt fogen is low, has secured its almost universal adoption. 



Two objections have been made to it, and both of them by the gen- 



emen to whom we are indebted for the labor of removing the practi- 



cal difficulties which necessarily surround this and every new process. 



.^he first is in the determination of nitrogen in bodies, where nitric 

 * c 'd is present. The per-centage is uniformly too low. No plan has 

 yet been suggested by which to surmount this difficulty. 



ih -e other is, generally, with bodies in which the proportion of nitro- 



r n ls la rge. It arises from the impossibility of perfectly controlling 



f e cur rent of evolved ammonia and other gaseous products. When 



'°m any cause the combustion proceeds for a moment slower than it 



"ould, or the first bulb of the apparatus becomes suddenly cooled, the 



and Chl0r ' c acid ^treats into this bulb, occasioning with the suddenly 



n a greatly increased surface, as the acid issues from the neck, an 



s tantaneous absorption of the ammonia— a partial vacuum and a conse- 



M ent rus h of the acid in jets into and across the bulb. Not unfrequently 



