ALKALOIDS. 395 



which are constituents of the gastric juice. It may 

 thus interfere, in a measure, with the process of diges- 

 tion. If pure muriatic acid were substituted for the 

 tartaric acid or cream of tartar, this objection would be 

 removed. The product of its action on soda is com- 

 mon salt. 



ORGANIC BASES. 



989. ALKALOIDS. Morphine and strych- 

 namesofsome nine, the former a useful medicine, and 

 fold al Wh the latter > tlie most dreadful of poisons, are 

 are they so examples of the alkaloids. They are 

 white crystalline bodies, but slightly solu- 

 ble in water. Most of them, like the protein bodies 

 above mentioned, contain the four organic elements ; 

 but they differ widely from these substances, in possess- 

 ing a positive chemical character. They are called 

 alkaloids from their resemblance, in certain properties, 

 to the alkalies of inorganic chemistry. Their action 

 upon vegetable colors is the same ; like the alkalies, 

 they also form salts with both organic and inorganic 

 acids. They are, in fact, true alkalies. Their alkaline 

 property does not, however, seem to depend on the 

 oxygen which they contain. Some of them, indeed, 

 do riot contain this element. It is highly probable that 

 certain of the alkaloids belong to the class of compound 

 ammonias mentioned in the first chapter of Organic 

 Chemistry. 



What is their 990. Their action on the human body 

 action on the does no t depend upon their alkaline char- 



human body ? 



Thdr anti- acter, but on other and peculiar properties 

 ***' belonging to each. The salts of the alka- 



