COLLIN. 207 



Tannin, . 46 or 26-5 

 Collin, 54 or 31-1 



100- 



According to Schiebel, 26-8 of tannin combine with 22-36 of 

 collin, when 100 parts of collin are precipitated by a great ex- 

 cess of infusion of 1 part of oak-bark in 9 parts of water. When, 

 on the contrary, we mix a very dilute solution of oak-bark with 

 a solution of collin, taking care not to throw down the whole of 

 the collin, we obtain a precipitate, which is deposited slowly, and 

 can scarcely be separated by the filter. This precipitate is com- 

 posed of, 



Tannin, . 59-25 or 26-5 



Collin, . 100- or 44-72 



It would seem from this that the first compound consists of 

 an atom of collin united to an atom of tannin, and the second of 

 two atoms of collin united to one atom of tannin. This would 

 make the atomic weight of collin, 22-36. 



According to Mulder, neutral tannate of collin is composed of, 

 Tannin, 10 



Collin, . 13 



23* 



The first attempt to analyze collin was made by Gay-Lussac 

 and Thenard. They mixed it with chlorate of potash, and burnt 

 the mixture, and determined the products.! The result was as 

 follows : 



Carbon, . 47-881 

 Hydrogen, . 7-914 

 Azote, . 16-998 

 Oxygen, . 27-207 



100-000 



\Vhat prevents us from drawing a satisfactory conclusion from 

 this analysis is our uncertainty about the purity of the collin, 

 examined. M. MulderJ has analyzed two specimens of collin, 

 which he purified in the following manner : The first specimen 



Ann. der Pharm. xxxi. 124. f Recherclies Physico-Chemiques, ii. 336. 

 \ PoggemlorPs Animlen, xl 279. 



