308 MATERIA MEDIC A AND THERAPEUTICS. 



having a peculiar heavy odour and nauseous-bitter acrid taste ; 

 yielding, when distilled with solution of potash, an alkaline 

 fluid, which has the peculiar odour of nicotin, and precipitates 

 with perchloride of platinum and tincture of galls. Not manu- 

 factured. 



Composition. Tobacco contains a most powerful alkaloid, 

 nicotin, and a concrete volatile oil, nicotianin, as well as 

 alkaline salts and other less important substances. Nicotin, 

 Ci H 14 N 2 , is a colourless oily-looking fluid, with an irritating 

 odour of tobacco, and an acrid taste. It forms salts with acids, 

 which, like nicotin itself, are readily soluble in water. 



Tobacco smoke contains the very smallest trace only of 

 nicotin, or none, but a number of volatile bodies, chiefly 

 pyridin compounds, such as pyridin, C 5 H 5 N; picolin, C 6 H 7 N; 

 lutidin, C7H 9 N ; collidin, CgHnN, which have somewhat the 

 same action as nicotin, but less severe. Hydrocyanic and 

 hydro-sulphurous acids, other simpler gases, creasote, etc., also 

 occur in tobacco smoke. 



Enema Tabaci. 20 gr. infused in 8 fl.oz. of Boiling Water for 

 one enema. 



ACTION AND USES. 

 1. IMMEDIATE LOCAL ACTION AND USES. 



Tobacco, taken by the mouth, is a gastro-intestinal 

 irritant, causing salivation, nausea, vomiting, severe colic, and 

 repeated evacuations. The same effects may follow tobacco 

 smoking, and the application of the leaf to the unbroken skin, 

 or of snuff to the nose. Tobacco smoking and snufling may 

 thus cause catarrh of the throat and stomach, and promote the 

 movement of the bowels facts of therapeutical interest. 

 Tobacco is never given by the mouth. Snuff is an errhine. 



Injected into the rectum, the Enema rapidly produces 

 peristaltic movements, with expulsion of gas and faeces, and 

 the specific effects now to be described. It has been used in 

 ileus and constipation. 



2. ACTION IN THE BLOOD. 



Nicotin very rapidly enters the blood from all surfaces, but 

 does not directly affect the corpuscles. 



3. SPECIFIC ACTION AND USES. 



All the organs are quickly reached by nicotin. It acts 

 chiefly upon the nervous structures, which it first stimulates, if 



