280 NON-NITROGENOUS NEUTRAL BODIES. 



The ammoniacal vapours and the very peculiar smell which it 

 developes during distillation indicate that it contains nitrogen. It 

 is not saponified by the alkalies. 



Serolin is obtained by extracting, with hot alcohol, blood which 

 has been dried, then boiled with water, and again dried. As the 

 alcohol cools the serolin separates in flocculi. 



CASTORIN. 



This body occurs in castoreum ; it crystallises from boiling 

 alcoholic solutions in small, four-sided needles, is pulverisable when 

 dried, melts at a temperature exceeding 100, is not saponifiable, 

 and is converted by concentrated nitric acid into nitrogenous, 

 crystallisable, castoric-acid. 



AMBREIN. 



Ambrein is the principal constituent of amber ; it crystallises 

 in white needles grouped in stars or wart-like shapes, melts at 37 5 

 cannot be saponified, and is converted by nitric acid into ambreic 



/, C 21 H 18 N 5 O 3 , which is crystallisable, and forms yellow salts. 



NON-NITROGENOUS NEUTRAL BODIES. 



Most of the substances belonging to this class closely resemble 

 one another in their empirical composition, and hence some of them 

 have received the name of " carbo-hydrates " ; for most of them 

 contain hydrogen and oxygen in the same ratio as these elements 

 are contained in water, so that if we suppose that they were com- 

 bined into water, carbon would be the only remaining element of 

 these bodies ; indeed, even the number of atoms of carbon in them 

 appears to be in accordance with a general rule, since in all the 

 formulae which as yet have been well established it is divisible 

 by 6. 



Considering their extremely analogous composition, it is naturally 

 to be expected that these bodies should present many chemical 

 properties in common with one another, various as their physical 



