294 BACTERIAL POISONS. 



sodium picrate is added, however, the pure adenine-mercury 

 picrate forms, since no hydrochloric acid is set free. 



Adenine-mercuric chloride, C5H4N5HgC], is thrown down 

 as a white, finely granular precipitate when a boiling aque- 

 ous adenine solution is treated gradually with concentrated 

 mercuric chloride solution. It is formed according to the 

 following reaction : 



C,H,N, + HgOl, = C.HAHgCl + HCl. 



That free hydrochloric acid forms can be ascertained by 

 methyl orange. Treated with ammonium hydrate the 

 chlorine is removed, and there is formed apparently the 

 compound C^H^NjHgOH. If dissolved in warm dilute 

 hydrochloric acid and allowed to crystallize, the double salt 

 C5H5N5.HCl.HgCl2 + 2II2O separates in long stellate silky 

 needles. 



Another mercury compound, CjH^I^sHgjClj, is obtained 

 when the precipitation takes place in the cold. The 

 precipitate is white, flocculent, and anhydrous. In this 

 reaction, as above, for each adenine molecule an equivalent 

 of hydrochloric acid is set free. This same body is also 

 produced when an adenine solution is boiled with a large 

 excess of mercuric chloride and as little hydrochloric as 

 possible to effect solution. On cooling small stellate needles 

 separate out, which do not lose their weight at 110°. It 

 can also be obtained by boiling the following compounds 

 with water. 



When adenine is boiled with a large excess of mercuric 

 chloride and much hydrochloric acid to completely dissolve 

 the precipitate that first forms, there is deposited on cooling 

 a crystalline product, which is variable in its composition, 

 and apparently consists of double salts of adenine and 

 mercuric chloride, such as CjHjNj.HCl.SHgClj and CjHjNj. 

 HCl.GHgClj. On boiling with water these rapidly de- 

 compose, forming the compound CjH^Nj.HgjClj. The 

 formation of a double salt, CsH^Nj.HOl.HgCIj + 2H2O 

 is described above. 



Adcniue-meroury cyanide, (C5H5N5)jHg(CN)2, separates 



