CHEMICAL SCIENCE. 283 



as the result of repeated experiment, that the ammonia found in the breath 

 varying so much in different persons at the same time, and in the same person 

 on different parts of the same day, and especially during the different condi- 

 tions of rest, exercise, and fatigue is not the mere return of the minute 

 portion inspired with the air. And if the air, when charged with its uniform 

 small quantity, fail so manifestly in supplying even the ammonia of the 

 breath, it must, of course, be rejected as the source of that additional 

 quantity which, at the same time, is found in every part of the body. The 

 source and formation of this alkali, therefore, is not ab extra. It seems, 

 perhaps, probable that animal ammonia is formed initially in the blood, of 

 which the two leading ingredients, albumen and fibrin, are equally rich in 

 nitrogen ; for this element exists in albumen, according to the analysis of 

 Gay-Lussac, in the proportion of 15'7 per cent, and of 19'9 per cent, in fibrin ; 

 while hydrogen, the other element of ammonia, is in the proportion of 7 per 

 cent, in each. The elements of the alkali, therefore, are present, and are 

 partly used for the formation of substances which are products of subtle 

 chemical action. Now, in the vegetable kingdom, the combination of these 

 elements for the formation of vegetable ammonias is a common and recog- 

 nized phenomenon; and similarly, to extend the views of Dr. Richardson, 

 in the exquisite balance of the chemical forces in the blood, it is arranged 

 that the blood should be feebly alkaline from fixed alkali or alkaline salt; 

 not sufficiently alkaline to hold fibrin in solution, but sufficiently so to leave 

 the volatile alkali free for this purpose, when formed in the closed chambers 

 of the circulation. I am, therefore, less disposed than my friend Dr. Rich- 

 ardson to leave this point an open question, but rather to meet his inquiry, 

 where is ammonia first formed? with the reply, in blood itself. It is with 

 some satisfaction I can add, that Dr. Richardson himself gives his imprima- 

 tur to this theory. If this view, then, be anything like an accurate state- 

 ment of the chemistry of nature, it confirms and harmonizes with the fact, 

 that the formation of ammonia is a continuous process. The portion which 

 maintains fluidity at a given moment does not remain to exercise this office 

 for hours or days, but its evolution direct from the blood is as necessary and 

 continuous an act as its formation. Hence it passes along with fibrin, in 

 fact carries the fibrin, as its solvent, to every part of the body, to supply its 

 daily waste ; and having performed this office, and satisfied every other de- 

 mand, the excess is evolved, in consequence of its equal diffusion, from every 

 excretory surface, and very largely, as I have heretofore proved, from the 

 surface of the lungs in the expired air of the breath. The evolution of am- 

 monia from the surface of the body may be proved by an interesting exper- 

 iment which happens not to have found a place in Dr. Richardson's admir- 

 able list of 400 save one. If a glass vessel, of suitable shape, having its inner 

 surface just moistened with hydrochloric acid, be placed on any part of the 

 body when warm with exercise, and, therefore, in a slight state of perspira- 

 tion, evolved ammonia will be taken up by the acid ; and if collected in a little 

 distilled water, the hydrochlorate may be received and crystallized by evap- 

 oration on a slip of glass for the microscope. The same experiment may 

 also be performed on the bodies of horses and other animals. The general 

 experiments which prove the existence of ammonia in breath are now too 

 well known to need description ; but there is a new experiment of consider- 

 able importance, as confirming the proof of these two propositions that 

 there is a volatile alkali evolved in the breath, and that this alkali, having 

 the property of maintaining the fluidity of the blood, is ammonia. Dr. Riclu 



