198 BACTERIA, YEASTS, AND MOLDS 



to be decomposed by bacteria, and if so, is such food 

 unwholesome in any respect ? 



We cannot regard any material as harmful simply 

 because it is a product of decomposition or contains such 

 products. A number of such decomposition products are 

 in more or less constant use. Alcohol is in a sense a 

 decomposition product of yeast. It certainly is used to 

 a very large extent, and probably, when used only in small 

 quantity, causes no very considerable injury. Vinegar 

 is also a decomposition product of bacteria, and is used 

 freely by the human race without injury. The flavors 

 of our high-priced butter are due to bacteria, and the 

 extremely valuable flavors of cheeses are due, in many 

 cases and perhaps in all, to decomposition products devel- 

 oped in the curd of milk by the action of certain micro- 

 organisms. Sauerkraut is a preparation which is allowed 

 to undergo an incipient decomposition the flavors of which 

 give the peculiar character to this food. That sauerkraut 

 is a harmless food product is, of course, perfectly evident. 

 In the general class of flavors known as gamy we have fla- 

 vors of decomposition produced by microorganisms. The 

 very common use of such partially decomposed meats, and 

 the fact that many persons are exceptionally fond of them, 

 are indications enough that they are not appreciably harm- 

 ful. These illustrations are suflficient to show that the 

 simple fact that food contains decomposition products 

 is not sufficient to make it unwholesome, since many 

 decomposition products are distinctly desirable in our 

 foods. The flavors of cheese in particular are very use- 

 ful, for when eaten with coarse bread they give relish 

 to otherwise rather tasteless foods. 



