380 C. G. Mitscherlich on [May 



(342-18 grs.) of filtered saliva of sp. gr. 1*0081 were mixed 

 with an excess of nitric acid, and precipitated by nitrate of 

 silver. The resulting precipitate amounted to 0*076 grm. 

 (1*17 grs.) chloride of silver =0*084 grm. (1*29 gr.) per 

 cent, of chlorine. 



The proportion of phosphoric acid is given under phos- 

 phate of lime. 



After the saliva has been treated with nitric acid until 

 all the organic constituents are destroyed, a residue re- 

 mains which is partly soluble in water, and affords a trace 

 of sulphuric acid with muriate of barytes. Saliva contains 

 therefore, muriatic acid, phosphoric acid, and sulphuric 

 acid. The potash being the stronger base is united with 

 the stronger acid, and the free soda being a weaker base, 

 is combined with its appropriate acid. There remain, 

 however, 0.094 potash in 100 parts, and 0*024 per cent, 

 soda to be neutralized by an organic acid. This is lactic 

 acid, which Mitscherlich has not been able to estimate in 

 the direct way. 



The salts contained in saliva appear to be 



Chloride of potassium 0*18 percent. 



Potash (combined with lactic acid) . 0*094 ,, 



Soda (with lactic acid) . . . . ' . 0*024 ,, 



Lactic acid ,, 



Soda (probably united to salivary mucus) 0* 164 ,, 



Phosphate of lime 0*0174 „ 



Silica 0-015 



Treviranus considered that the dark red colour which is 

 produced by adding to the saliva muriate of iron, was owing 

 to the existence, of what he called acid of the blood. 

 Gmelin ascribed this property to the presence of sulpho- 

 cyanic acid. A single drop of the solution of muriate of 

 iron, occasions a dark red colour in a great quantity of 

 saliva. By agitation the mucus separates, and a fine dark 

 red colour is exhibited in the saliva. Saliva from the 

 mouth, gave the same result as the saliva from the fistula, 

 and was the same both in the acid and alkaline states of 

 that fluid. 



In the examination of the organic constituents, high 

 temperature is to be avoided, because they are altered by 

 such means. The evaporation of the water and alcohol is 



