344 Dr. Henry on the Analysis of some of [Nov. 



tain any, or if any, only a very small portion of morphium," he 

 is I think particularly unfortunate. If Mr. Battley mean to sav 

 that the distilled water in which he had infused the opium did 

 not contain any morphia, how does it happen that so many 

 have obtained it from such a solution ? and if he admit that it 

 does contain morphia, where is the corresponding quantity 

 from the opium infused in spirit, if it be not held in solution by 

 the spirit? Unless Mr. Battley can state by what means the 

 morphia can make its exit, I must consider that his experi- 

 ments prove directly the reverse of his conclusions. 



W. A. South. 



Article VI. 



Experiments on the Analysis of some of the Aeriform Compounds 

 of Nitrogen. By William Henry, MD. FRS. &c. &c. 



(Coiulu chd from p. 303.) 



2. — Of the Analysis of Nitric Acid. 



The evidence of the composition of nitric acid, on which the 

 view, now most commonly taken of its constitution, is founded, 

 is derived almost entirely from synthetic experiments. Sir H. 

 Davy long ago stated,* that 4 in volume of nitrous gas and 2 of 

 oxygen gas, condensed in water, absorb 1 in volume of oxygen 

 to become nitric acid. But 4 in volume of nitrous gas being 

 equivalent to 2 of nitrogen and 2 of oxygen, the whole oxygen 

 in nitric acid will be 5 volumes to 2 of nitrogen, or 2-5 volumes 

 to one volume. The smallest proportion of nitrous gas found 

 by Mr. Dal ton to unite with oxygen gas, viz. 13 nitrous to 10 

 oxygen, gives the ratio in volume of nitrogen to oxygen, in nitric 

 acid, as 1 to 2*53.*t' M. Gay-Lussac also determined by the test 

 of the red sulphate of manganese, which is deprived of colour by 

 the nitrous but not by the nitric acid, that the latter acid only is 

 generated when 134 measures of nitrous gas are made to com- 

 bine with 1 00 of oxygen, proportions which indicate almost 

 exactly 1 volume of nitrogen and 2'5 volumes of oxygen in nitric 

 acid .J 



But though the synthetic proofs rest on such high authori- 

 ties, and all tend to the same point, yet it is desirable to confirm 

 evidence of this nature by that of analysis, whenever it can be 

 obtained; and the object appeared to M. Gay-Lussac suffi- 

 ciently important to induce him to seek for this additional proof 

 in two different ways, viz. by the decomposition of nitrate of 



* Elements of Chemical Philosophy, p. 2C4. 



t New System, p. 328, 364. 



% Ann. de Chim, et de Phys. i. 404. 



