28 BACTERIOLOGICAL METHODS 



removed from the oven showed no typhoid colonies and very few 

 of other kinds. Cultures taken at a distance of half an inch from 

 the surface showed a few colonies of the typhoid bacillus, most of 

 the organisms having been killed. Cultures from a depth of 

 2^ in. showed abundant colonies of typhoid bacilli. In these 

 cultures the typhoid colonies were identified by their appearance 

 on Endo medium and Russell medium and also by agglutination 

 by an ti- typhoid serum." 



Dr. Sawyer sums up the experimental evidence as follows: 



"The laboratory experiments completed the explanation of the 

 Hanf ord outbreak by showing that the sauce used in making the 

 Spanish spaghetti was a good culture medium and that the dish 

 had not been sterilized after leaving the house of the typhoid 

 carrier. 



" Moreover, it was demonstrated that cooked dishes must 

 be considered as possible conveyors of infection unless it can be 

 shown that the method of cooking would produce complete 

 sterilization. The slowness with which heat penetrates dishes 

 like the Spanish spaghetti shows that very prolonged heating 

 would be necessary for sterilization of large dishes of such food. 

 Ordinary baking merely incubates the interior of these masses 

 of food." 



This report by Dr. Sawyer is of special significance to the 

 food bacteriologist as it illustrates two very important factors 

 concerned in the study of food sanitation: First, the possible 

 contamination of food materials through carriers of disease, 

 and secondly, the necessity of studying more carefully our pres- 

 ent methods of sterilization (of food materials) through the 

 agency of heat. As will be more fully set forth in subsequent 

 chapters, the examination of canned foodstuffs shows that sterili- 

 zation is far from complete in the great majority of cases. 



In addition to the more or less acute infections traceable to 

 the consumption of contaminated food products, there are the 

 multitudinous infections which are of slow development or 



