118 Nature of the Acid and Saline Matters in Animals. [Aug. 



tionable method by which their truth might not only be satis- 

 factorily demonstrated, but at the same time that the relative 

 quantities of the different principles might be determined : after 

 various attempts, the following processes were adopted for these 

 purposes. 



The contents of the stomach of a rabbit, fed on its natural 

 food, were removed immediately after death, and repeatedly 

 digested in cold distilled water till they ceased to impart any 

 thing to that fluid. The whole of these different portions of 

 fluid, which always exhibited strong and decided marks of 

 acidity, were then intimately mixed together, and after being- 

 allowed to settle, were divided into four equal portions. 1. The 

 first of these portions was evaporated to dryness in its natural 

 state, and the residuum burnt in a platinum vessel; the saline 

 matter left was then dissolved in distilled water, and the quan- 

 tity of muriatic acid present determined by nitrate of silver in 

 the usual manner ; the proportion of muriatic acid in union with 

 afxed alkali, was thus determined. 2. Another portion of the 

 original fluid was supersaturated with potash, then evaporated to 

 dryness, and burnt, and the muriatic acid contained in the 

 saline residuum determined as before. In this manner the total 

 quantity of muriatic acid present in the fluid was ascertained. 

 3. A third portion was exactly neutralised with a solution of 

 potash of known strength, and the quantity required for that 

 purpose accurately noticed. This gave the proportion of free 

 acid present ; and by adding this to the quantity in union with 

 a fixed alkali, as determined above, and subtracting the sum 

 from the total quantity of muriatic acid present, the proportion 

 of acid in union with ammonia was estimated. But as a check 

 to this result, the third neutralised portion abovementioned 

 was evaporated to dryness, and the muriate of ammonia expelled 

 by heat, and collected. The quantity of muriatic acid this con- 

 tained was then determined as before, and was always found to 

 represent nearly the quantity of muriate of ammonia as before 

 estimated ; thus proving the general accuracy of the whole 

 experiments beyond a doubt. 4. The remaining fourth portion 

 of the original fluid was reserved for miscellaneous experiments, 

 and particularly for the purpose of ascertaining whether it con- 

 tained any other acid besides the muriatic. The experiments 

 abovementioned seemed to preclude the possibility of the pre- 

 sence of any destructible acid; and the only known fixed acids 

 likely to be present were the sulphuric and phosphoric ; the 

 muriate of barytes, however, neither alone, nor with the addition 

 of ammonia, produced any immediate precipitate,* showing the 



* It may be proper to remark, that ammonia, after some time, caused a flocculent 

 precipitate, consisting of the earthy phosphates in union with vegetable and animal mat- 

 ter, and that after combustion, traces of sulphuric acid, the result of that process, were 

 very perceptible. But it is evident, from the experiment related in the text, that nei- 

 ther of these acids previously existed in the original fluid in a free state. 



