364 CASE OF SARCINA VENTRICULI. 



" The proportion of acetic acid in tlie twice-distilled fluid 

 was ascertained in the usual way with the alkalimeter, by- 

 finding the quantity of carbonate of potass required to 

 neutralise it, Tt was found by several trials, that, on an 

 average, an ounce of the liquid neutralised 0-4 gr. of the 

 carbonate ; a quart (32 oz.) would therefore neutralise 12-8 

 gr. which correspond to 9 gr. of the hydrated (crystallisable) 

 acetic acid HO + C4 Hs O3. 



" The liquid remaining in the retort after the first distilla- 

 tion was now examined and found still to be strongly acid. 

 This property was traced in part to the presence of a small 

 portion of free hydrochloric acid. The large amount of 

 chloride of sodium which accompanied it made it difficult of 

 detection ; nor did I succeed in ascertaining its proportion. 

 But I satisfied myself that it occurred only in small quantity 

 by the following experiments : — Some ounces of the filtered 

 liquid, along with a portion of red oxide of lead, were placed 

 in a flask provided with a bent tube dipping into a wine- 

 glass, containing a very weak infusion of blue cabbage. The 

 flask was then heated till the liquid boiled, and, by the 

 quantity of vapour sent through the infusion, made the latter 

 boil also. The cabbage was reddened, but not perceptibly 

 weakened in tint ; whereas, had free hydrochloric acid been 

 present in any quantity, it must have been deprived of 

 hydrogen by the metallic oxide and chlorine evolved. When 

 the experiment was repeated, with the addition to the flask of 

 a little sulphuric acid, the infusion was bleached in a few 

 seconds. A similar experiment was made with the substitu- 

 tion of a solution of hydro-sulphuret of ammonia for the 

 vegetable infusion, with a view to convert any evolved 

 chlorine into muriate of ammonia. The hydro-sulphuret was 

 then evaporated to dryness, and nitrate of silver added; a 

 precipitate of sulphuret and chloride of silver fell, but when 

 the latter was dissolved out by ammonia, its amount was 



