1 88 ELEMENTS OF PHYSIOLOGY 



safety which has been brought about by aseptic surgery 

 depends upon excluding the germs of disease. 



326. Alkaloids. There is another class of organic 

 poisons, closely related to ptomaines, which should be 

 mentioned. They are vegetable and animal alkaloids. 

 Ptomaines are formed by bacteria in dead organic matter ; 

 toxins are formed by bacteria in living bodies. The alka- 

 loids are formed without bacteria, but are waste products 

 formed in living animals and plants by their life processes. 

 Among vegetable alkaloids may be mentioned strychnine 

 of nux vomica, daturine of the jimson weed, atropine of 

 the belladonna, nicotine of tobacco, podophyllin of the may- 

 apple root, caffeine of the coffee plant, quinine of the 

 Peruvian bark or cinchona tree, theobromine of coca, theine 

 of tea, morphine of the poppy, etc. They form the active 

 principles of most medicines, and are given for either a 

 narcotic (deadening) or a stimulating (exciting) effect. 



327. The dangerous properties of most medicines cause 

 us to wonder why some people experiment with them so 

 rashly without professional advice. Persons who would 

 not think of playing the part of a lawyer, or a theologian, 

 or even of trying to doctor a horse, if the horse was of 

 much value, do not hesitate to prescribe the most virulent 

 remedies for their friends and families. The course in 

 medical schools in the United States is now usually four 

 years in length. Most of our physicians are not mere pill- 

 peddlers and prescribers of drugs, but are capable of 

 advising their patients in every aspect of their physical 

 welfare, and their advice should be taken and paid for as 

 readily as their drugs. 



328. Taken in large doses, alkaloids are virulent poisons. 

 The chief animal alkaloids are xanthin, and other com- 

 pounds related to uric acid. Very little is known about the 

 alkaloids and their properties. 



329. A Curious Theory. There is an artless theory com- 



