382 C. G. Mitscherlich on [May 



Ammonia acts like acetic acid. Caustic potash produces 

 an imperfect solution. 



The matter soluble in water but insoluble in alcohol 

 (sp. gr. 0*863) is called by Berzelius salivary matter. 

 Gmelin made many experiments upon this substance, which 

 differ considerably from those of the Swedish chemist. 

 The salivary matter in neutralized saliva, acts strongly 

 acid upon test paper, but without neutralization, red lit- 

 mus paper becomes blue in the solution. It is of a yel- 

 lowish brown colour, but when the alkali is not saturated, 

 and it is kept from the moisture of the atmosphere, the 

 colour is white. The yellowish brown salivary matter dis- 

 solves in water, and when carefully evaporated does not 

 re-dissolve, but always leaves a trace of an insoluble sub- 

 stance. The white salivary matter, on the contrary, re-dis- 

 solves completely in water after evaporation to dryness. 

 Alcohol occasions a white precipitation which is dissolved 

 by water. 



By the application of a strong heat carbonate of ammonia 

 is driven off, and the carbonaceous matter contains potash 

 and soda. No effect is produced upon the aqueous solution 

 of salivary matter by sulphuric, nitric, or hydro-chloric 

 acids, or by ammonia or caustic potash. The same is the 

 case with corrosive sublimate and muriate of iron. Nitrate 

 of silver gives a white precipitate which is re-dissolved by 

 ammonia. 



If the salivary matter is obtained without neutralizing 

 the free alkali, then acetate of lead affords a copious white 

 precipitate which does not dissolve by boiling, becomes a 

 slight muddiness by the addition of water, and wholly dis- 

 appears by an excess of acetic acid. If the saliva is pre- 

 viously neutralized by sulphuric acid, the salivary matter 

 contains sulphuric acid salts, and when the sulphuric acid 

 is removed exhibits the characters already mentioned. 



Infusion of galls does not alter the solution of salivary 

 matter. 



The matter soluble in water and insoluble in absolute 

 alcohol is no longer soluble in alcohol of sp. gr. 0*863, and 

 consists principally of salts with some animal matter of a 

 yellowish colour. The solution of this substance is not 

 affected by muriate of barytes, corrosive sublimate, muriate 

 of iron, sulphuric acid, muriatic acid, nor by infusion of galls. 



