260 



Substances 



found. 



These vary in 

 their propor- 

 tions. 



The analysis 

 very nice and 

 difficult. 



ANALYSIS OF NEUTRAL SALT8. 



During these operations the ammonia is for the most part 

 extricated, as well as the sulphuric acid, in the state of sul- 

 phite of ammonia, and the phosphoric acid is left tolerably 

 pure. Caustic potash however still evolves a little am- 

 monia. 



Thus, beside the phosphate of lime, there are in human 

 bones, as well as in those of animals, phosphates of mag- 

 nesia, iron, manganese, silex, and alumine. The last is in 

 very small quantity; yet enough for its presence to be fully 

 recognized and established. 



It may be supposed, that in this method of analysis human 

 bones will exhibit some variation in the proportions of the 

 substances, according to the age, constitution, state of 

 health, and general diiference of the persons to whom they 

 belonged. 



It is eqwally essential to observe, that, though this ana- 

 lysis exhibits a set of experiments simple enough in their 

 description, it must be reckoned among the most delicate 

 and difficult analyses, on account of the number of succes- 

 sive operations it includes, and the precision it requires. 



IV. 



Letter from 3Ir, Berzelivs to iJ/r. Berthollet on the 

 Analysis of different Salts*. 



Two proposi- jLN studying Mr Richter^s work, ** On modern Subjects of 



tionsofconni- Chemistry", Part I— X, 1795—1800, I found in it two 



derable im- . 



l)ortanceto propositions, which appear to me of great importance to 



thetheoiyof ^^le theory of affinities. These are: 1. That all neutral 

 salts, which remaui neutral when their solutions are mixed, 

 are so composed, that the quantities of the different bases, 

 that saturate one of the acids present in the mixture, follow 

 the same proportions in saturating the other acids : 2. That 

 a metallic neutral salt, the metal of which is precipitated 

 by another more combustible metal, changes its metal only; 



* Annales de Chim. vol. LXXVII, p. 63, 



while 



