400 VEGETABLE DRUGS 



in paralyzing respiration, and is said to be formed more in 

 pipe smoke, while, in the smoke of cigars, the more harm- 

 less coUidine is produced by dry distillation. Nicotine 

 exists to a very slight degree in Turkish tobacco. 

 i?06e.— Nicotine, H. & C, gr.^-^V (.001-.003). 



ACTION OF TOBACCO AND NICOTINE. 



Action External. — Tobacco is a local anodyne, antiseptic 

 and parasiticide. 



Action Internal. — Digestive Tract. — The physiological 

 effect of tobacco is due to nicotine. Nicotine increases peri- 

 staltic action and, in large doses, causes tetanic spasm of 

 the intestines, even when it is injected into the blood. In 

 toxic quantities nicotine is a powerful gastro -intestinal irri- 

 tant, and produces the usual symptoms of pain, vomiting 

 (in animals capable of the act), purging and collapse. 



Circulation. — When nicotine is added to blood recently 

 withdrawn from the body, this fluid assumes a dark hue, 

 and the corpuscles quickly disintegrate. The blood, in 

 poisoning, becomes dark colored, owing to asphyxia, but 

 regains its arterial tint when removed from the body and 

 shaken with air. It is only in poisoning by enormous quan- 

 tities that changes in the red blood corpuscles can be 

 detected microscopically, although the spectrum of haemo- 

 globin is altered in poisoning, proving that the corpuscles 

 are in some way affected. Experiments with nicotine upon 

 frogs show that there is produced a primary fall in blood 

 pressure and. pulse rate, followed by a rise in both, only to 

 be succeeded by a return to the original depressed condition 

 caused l?y the alkaloid. 



The exact physiological data accounting for these circu- 

 latory phenomena have not been worked out, although they 

 are probably dependent upon stimulation followed by 

 depression of the inhibitory apparatus and vasomotor sys- 

 tem. 



Nervous System and Muscles.— "^iGoiuiQ first stimulates, 

 and then paralyzes the cells of the inferior cornua and motor 



