35 BACTERIA. 



which also produces some of the symptoms of that condition ; 

 and two other alkaloids both of which give rise to certain 

 definite symptoms, acting physiologically somewhat like 

 strychnine. The importance of the presence of these 

 substances in pure cultivations of pathogenic organisms 

 can scarcely be overestimated. In the vegetable kingdom 

 there are recognized whole series of substances that have 

 an alkaline reaction, combine with acids to form salts, 

 are evidently formed by the protoplasm of the plants in 

 which they are found, and which, injected into the tissues 

 of an animal or taken by the stomach, exert a most 

 energetic poisonous action either upon the end organs in 

 muscles or upon the muscles themselves. Of these we may 

 take such well-known examples as strychnine, atropine, 

 nicotine, cinchonine, thebaine, morphine, brucine, and others. 

 They are all of them built up by vegetable cells and all exert 

 a specific action on animals. Similarly it is found that bacteria 

 minute vegetable organisms can build up substances, as 

 they grow in dead or living animal tissues in which they are 

 living as saprophytes or parasites, which substances exert 

 a most deadly influence on the nerve centres or the parts 

 above mentioned of animals in which they are formed or 

 into which they may be injected, but in addition have an 

 extremely injurious local " caustic " influence, giving rise in 

 many cases to the death of the tissues with which they may 

 come in contact at the points where the poison is formed, or 

 at the seat of inoculation. Thus tetanine is a substance that 

 appears to act through the nervous system much as does the 

 alkaloid strychnine, whilst in sepsine, material formed by 

 those bacteria that are found in a local abscess, we have a 

 powerful acrid substance which by its caustic action causes the 

 death of the cells with which it is allowed to come imme- 

 diately in contact. Some of the most deadly of the poisons 

 formed by micro-organisms, however, are not of the nature 

 of alkaloids, but are said to belong rather to the classes of 

 globulins and albumoses. A number of them, however, 

 give some of the reactions of the alkaloids, but they must 

 not on that account be looked upon as belonging to that 

 group. Brieger includes under the term ptomaine all 

 nitrogenous bases that are formed by the action of bacteria, 

 such of those as are poisonous being spoken of as toxines. 

 It thus happens that certain ptomaines that are formed 



