388 CONSIDERATION OF CARBON COMPOUNDS. 



pounds containing, besides the three elements named, also oxygen), 

 and show their derivation from ammonia to a more or less marked 

 degree, as, for instance, in their power to combine with acids without 

 elimination of water, to combine with platinic chloride to form 

 insoluble double compounds, etc. 



The compounds formed by the direct combination of alkaloids 

 with acids are, in the case of oxygen acids, named like other salts of 

 these acids, for instance, sulphates, nitrates, acetates, etc. In the 

 case of halogen acids, however, a different method has been adopted, 

 because it would be incorrect to apply the terms chlorides and 

 bromides to substances formed not by the combination of chlorine or 

 bromine with other substances, nor by the replacement of hydrogen 

 in the respective hydrogen acids of these elements, but by direct 

 combination of these acids with the alkaloids. The terms hydro- 

 chloride and hydrobromide would have been very appropriate, but the 

 terms hydrochlorate and hydrobromaie have been adopted by the 

 U. S. P. for the compounds obtained by direct union of alkaloids 

 with hydrochloric and hydrobromic acids. 



Alkaloids are found in the leaves, stems, roots, barks, and seeds of 

 various plants ; it often happens that a certain alkaloid is found in 

 the different species of one family, and it is also often the case that 

 various alkaloids of a similar composition are found in the same 

 plant. 



General properties of alkaloids : 



1. They combine with acids (without elimination of water) to form 

 well-defined salts, and are set free from the solutions of these salts 

 by alkalies and alkali carbonates. 



2. Those containing no oxygen (amines) are, in most cases, volatile 

 liquids, those containing oxygen (amides), are non-volatile solids. 



3. The volatile alkaloids have a peculiar, disagreeable odor remind- 

 ing of ammonia ; the non-volatile alkaloids are odorless. 



4. Most solid alkaloids fuse at a temperature above 100 C. (212 

 F.) without decomposition, but are decomposed when the heat is 

 raised much beyond the fusing- point. 



5. Most alkaloids are insoluble, or nearly so, in water, but soluble 

 in alcohol, chloroform, benzene, acetic ether, and many also in ether. 



6. The chlorides, sulphates, nitrates, acetates (and most other salts) 

 of alkaloids are either soluble in water, or in water which has been 

 slightly acidulated, and also in alcohol ; but they are insoluble, or 

 nearly so, in ether, acetic ether, chloroform (except veratrine and 



