104 THE SECRETIONS: 



caustic potash added to the residue ; by this means the pre- 

 sence of ammonia was established beyond a doubt. On digesting 

 another portion with oxide of lead, and moistening the dried 

 mass with sulphuric acid, vapours of acetic acid were developed. 

 A third portion, which was treated with lime water, became 

 turbid, in consequence of the presence of carbonic acid. For 

 the purpose of determining the solid constituents, Anselmino 

 made use of sweat that had been collected by clean sponges from 

 the vapour-bath ; it was turbid, and had a strong though by no 

 means a constant odour. After the distillation of a portion of 

 the filtered liquid in the steam-bath, acetate of ammonia was 

 found in the fluid that had collected in the receiver. A very 

 small amount of solid residue (from O5 to 1'25J) was left after 

 evaporation of the sweat. Anselmino extracted the solid resi- 

 due with alcohol of -833, evaporated the alcoholic solution 

 to dryness, and then, by means of anhydrous alcohol, extracted 

 from the saline residue an acid, extract-like matter, similar to 

 the alcohol-extract of flesh, and containing free acetic acid, 

 acetate of potash, and animal matter precipitable by tannic 

 acid. Berzelius conceives the free acid of this extract (like the 

 free acid in extract of flesh,) to be lactic acid. Now I will not 

 assert that the sweat always contains free acetic acid, but I cer- 

 tainly have observed cases in which the odour clearly showed 

 that the free acid was principally the acetic ; lactic acid may, 

 however, still be always present. The occurrence of acetic acid 

 in sweat is placed beyond a doubt by my experiments. The 

 matters which are undissolved by anhydrous alcohol are princi- 

 pally chlorides of sodium and potassium, and spirit- extract ; the 

 latter is not precipitated by chlorine, protochloride of tin, or 

 bichloride of mercury. In this investigation Anselmino seems 

 to have overlooked, as Berzelius remarks, the hydrochlorate and 

 lactate of ammonia. All that is insoluble in alcohol may be 

 dissolved in lukewarm water, with the exception of a gray mat- 

 ter; this aqueous solution contains sulphates and an animal 

 matter precipitable by tannic acid, and perchloride of tin, (water- 

 extract.) The gray insoluble matter leaves on incineration a 

 considerable amount of phosphate, together with a little car- 

 bonate of lime. 



Anselmino has consequently arrived at results which entirely 

 correspond with my own, excepting only that I could not in every 



