BASIC BODIES. 127 



founded on certain chemical facts, may seem to indicate a direction 

 for future experimental investigations, but cannot warrant us in 

 advancing further in this domain of the imagination. We post- 

 pone for the present entering into the consideration of other 

 hypotheses tending to elucidate the origin of the group of atoms 

 conjugated with oleic acid. 



We must necessarily defer our remarks on the possible use of 

 cholic acid in the animal body, till we treat of the uses of the con- 

 jugated cholic acids and of the bile generally. 



NITROGENOUS BASIC BODIES. 



Substances of this nature occur principally in the vegetable 

 kingdom ; those requiring a notice in animal chemistry are almost 

 all only artificial products of known animal matters: in as far how- 

 ever, as they, like many of the acids which have been already 

 described, throw much light on the constitution of the bodies from 

 which they are derived, they must not be passed over in a work of 

 this nature. As there exists no true alkaloid without nitrogen, the 

 basicity of this class of bodies may be regarded as essentially 

 depending on the amount of nitrogen which they contain ; and in 

 further confirmation of this view, we may bring forward the fact 

 that the saturating power of these bodies is perfectly independent 

 of the amount of oxygen which they contain. Indeed it rather 

 depends in most cases on the amount of nitrogen ; that is to say, 

 1 equivalent of the nitrogen of the base requires 1 equivalent of 

 acid in order to form a neutral salt. Berzelius has, therefore, 

 advanced the opinion that the nitrogenous bases are merely 

 ammonia-compounds, with either a non-nitrogenous or a nitro- 

 genous body as an adjunct. The principal argument in favour of 

 .this view is, that these bases, like pure free ammonia, cannot unite 

 with oxygen acids, without simultaneously assimilating an atom of 

 water, but that, on the other hand, they combine with hydrochloric 

 and other hydrogen acids, without a separation of water : finally, 



