366 Professor Connell on the 



late experiments, its muriate does not contain the elements of 

 ■"vater, whilst its oxysalts do. 



By late experiments, also, the xanthic oxide (xanthine) 

 Q5 Q2 -^5 JJ5 appears to be a base of a similar character, although 

 there seems to be this peculiarity, that it requires two of the 

 single atoms of the base, which combine with hydracids to 

 unite with the elements of one atom of water, and pass into 

 the oxygen base series. 



If we leave the series of bases and turn to that of halogens 

 (salzbilder), we discover the same proofs of approaches to a 

 type differing in the degree of perfection to which the result 

 is carried. After the simple halogens, chlorine, bromine, &c., 

 the most perfect and least complex of the compounded ones is 

 cyanogen C^ N. As ammonia is modelled on the simple 

 metals, so cyanogen is moulded on the simple halogens, and 

 analogy guides their respective combinations. Hydrocyanic 

 and cyanic acids have their prototypes in the analogous com- 

 binations of the simple halogens, although they fall behind 

 them in the perfection of the result. 



Next come ferrocyanogen and sulphocyanogen. In these 

 the analogy to the simple halogens has been followed out in 

 considerable perfection, although the constitution is very com- 

 plex, and these compound halogens themselves have not yet 

 been distinctly isolated. The type is quite manifest. 



Mellon C" N* ranks next, with its hydracid C*' N^ H, and 

 numerous haloid salts. 



Three well-known essential oils, the pure oils of spircea ul- 

 maria, bitter almonds, and cinnamon, connect, in a very in- 

 teresting manner, inorganic and organic nature, by presenting, 

 particularly the first mentioned, a strong analogy between 

 simple halogens and compound ones, although not yet isolated. 

 The spiroil or salicyle series has an analogue for almost every 

 combination of chlorine or iodine. Its hydracid C^* H^ 0^-}-H, 

 has weak but decided acid properties. Its haloids are true 

 salts often ■ crystallized. The other two series are less per- 

 fectly developed, the haloid compounds being awanting, and 

 the hydrogen combinations scarcely acids. The type, indeed, 

 of cinnamyle, if isolated, would rather be such a substance as 

 phosphorus, than the more perfect halogens ; for its hydrogen 



