24 BACTERIOLOGICAL METHODS 



1. Chemical (decomposition) changes in foods and drugs induced by the various 

 organic infecting agents, as bacteria and other living organisms, which render such 

 substances unfit for human use or which render them dangerous for human use. 



2. Foods and drugs as actual or possible carriers of infecting agents which are 

 or may be dangerous to life or which may or might be injurious to the physical 

 well-being of the human species. 



It goes without saying that the food bacteriologist must pro- 

 ceed carefully in order that there may be no hasty decisions re- 

 sulting in the condemnation of food products which are not in- 

 jurious. There is, however, little excuse for hasty or unjustifi- 

 able passing of judgments as regards the quality of food. Bac- 

 teriological and toxicological methods have been sufficiently 

 perfected so that the careful analyst need not make unfair or 

 unwarranted decisions. The men entrusted with the critical 

 examination of foods and drugs as to their fitness for human 

 use should be investigators of authority and should have had 

 wide range of practical as well as laboratory experience, and they 

 should furthermore be possessed of good judgment. While 

 the condemnation of food materials should not be hasty it should 

 on the other hand not be too tardy or conservative. The prime 

 object of the work by the food bacteriologist is to protect the 

 consumer, not the dealer or manufacturer. This very important 

 point is most unfortunately not properly heeded with the result 

 that some of the work done in the administrative laboratories is, 

 or appears to be, in the interests of the dealer or manufacturer. 



A goodly number of infections enter the human system by way 

 of the mouth with the ingested foods and drinks. Food substances 

 form excellent pabula for the bacteria and other parasitic agents 

 which enter the digestive tract or which may already have entered. 

 Foods and drinks are exposed to infection in a great variety of 

 ways. For purposes of illustration we may cite bread, the so- 

 called " staff of life," as one of the foods which is liable to infec- 

 tion. It may be assumed that the loaf of bread, when it is taken 

 from the oven, is entirely sterile and free from living organisms 

 of all kinds. Just as soon as the loaf is cool enough to permit it, 



