Vegetable Albumen, Fat and Starch. 419 



of the distilled fluid just described ; but in neither instance 

 could a trace of hydrochloric acid be detected by nitrate of 

 silver. 



With the liquor remaining in the retort, three experiments 

 were made to determine the possible amount of free hydro- 

 chloric acid, on the supposition that the preceding experi- 

 ment did not serve as evidence to prove the impossibility of 

 its presence. Three equal portions of the fluid were mea- 

 sured out, to the extent of two fluid ounces in each portion. 



1. To the first portion, a solution of nitrate of silver was 

 added until a precipitate ceased to fall ; pure nitric acid was 

 then mixed with the liquid, and the temperature raised to 

 the boiling-point. The precipitate was filtered, washed and 

 weighed. 



2. The second portion was evaporated to dryness and ig- 

 nited ; the residue was dissolved in water and precipitated by 

 nitrate of silver, the solution being acidulated with nitric acid 

 and brought to the boiling-point. 



3. The third portion was exactly neutralized with caustic 

 potash, evaporated and ignited ; the residue dissolved in water, 

 and the solution precipitated by nitrate of silver. 



The results of these experiments are indicated in the fol- 

 lowing table in grains : — 



The atomic weights here employed are Dr. Thomson's: 

 Oxygen = 1 • 

 Hydrogen = '125 

 Chlorine =4^ 

 Silver =13i 



The correspondence between the first and third experiments 

 shows that in the first no organic substance had been in union 

 with the silver, which was precipitated by chlorine alone, and 

 that there is no evidence from these results of free muriatic 

 acid being present. The conclusion is the reverse, since if any 

 free muriatic acid had been neutralized by the potash the third 

 experiment ought to have given an inferior quantity of chlo- 

 ride of silver, because the sal-ammoniac ought to have been 

 sublimed. The potash which was added, I conceive, in the 

 third experiment, united with an organic acid; the salt foimed 

 was decomposed by the incineration, and the potash united to 

 the chlorine previously in union with ammonia ; for that sai- 



2 F 2 



