PTOMAINE POISONING 199 



Bacterial Poisons in Foods 



But, on the other hand, there are unquestionably some 

 such products which are harmful and which, even though 

 present in small quantity, may be decidedly harmful, or 

 even poisonous. When certain kinds of microorganisms 

 grow in food material they give rise to a class of decom- 

 position products which have been known under the gen- 

 eral name of ptomaines. These ptomaines are chemical 

 bodies of great complexity with whose chemical nature we 

 are not in this work concerned. It is sufficient for our 

 purpose to know that they are usually the result of bac- 

 teria growing in animal products, and, while some of them 

 are quite harmless, others are of an intensely poisonous 

 nature. If such bodies develop in food they may render it 

 unwholesome, or even fatally poisonous. To such poison- 

 ous decomposition products are due instances of poison- 

 ing from eating cheese, quite a number of which are on 

 record. A similar cause explains the still larger number 

 of cases of ice-cream poisoning, when many people have 

 been rendered seriously and even fatally sick by the eat- 

 ing of ice cream. Similar effects have sometimes resulted 

 from the use of -milk, although such cases are rare. Many 

 cases of poisoning are recorded from the use of meats, fish, 

 and sometimes other foods. 



The poisoning in all such cases must not be confused 

 with diseases produced by bacteria. Sometimes food may 

 contain disease germs, and these may enter the body when 

 the food is swallowed, and by growing inside of our bodies 

 produce disease. (See Chapter XIV.) But in cases of 

 poisoning from eating food the bacteria grow simply in 



