BACTERIOLOGICAL ASPECTS OF DEHYDRATION 123 



sample. As would be expected, there was a decrease in the num- 

 ber of bacteria. The mold spores remained practically constant. 

 The practical result of this somewhat extended investigation 

 was to prove beyond doubt that paper or wood pulp containers 

 of good quality may be used with safety under the ordinary con- 

 ditions pertaining in the temperate zones. Their cheapness and 

 availability will help to establish the industry commercially. No 

 invasion of organisms from outside takes place, and the varia- 

 tions in temperature and humidity of the outside are accompanied 

 by a corresponding but perhaps smaller rise and fall in moisture 

 in the food materials. Eventually an equilibrium with the air 

 is reached. It is doubtful if the moisture would ever reach the 

 point sufficient to bring about bacterial decomposition. On the 

 other hand, these containers do not appear to be suitable for use 

 in hot moist conditions for the reasons that have been pointed 

 out through the results I have given. 



DANGER OF FOOD POISONING OUTBREAKS THROUGH USE OF 

 DEHYDRATED FOODS 



Our attention has been directed during recent years to a num- 

 ber of cases of so-called food poisoning. These are now generally 

 recognized as infections with some one or more of a number of 

 organisms, among which may be named B. paratyphosus A and 

 B, B. enteritidis, B. welchii, B. suipestifer and B. botulinus. The 

 fact that dehydrated foods are not cooked or sterilized as they 

 are prepared and packed for sale, brings up a question as to pos- 

 sible dangers from this source. Moreover, the methods of gar- 

 dening employed in the production of vegetables for dehydration 

 in some parts of the country, as in California, where Japanese 

 gardeners produce them in large quantities, make it conceivable 

 that the vegetables may reach the dehydration establishment in- 

 fected with some of these bacteria or with B. coli or B. typhosus. 



This matter seemed to be of sufficient practical importance to 

 warrant a careful study of the effect of drying on these organisms. 

 Two sets of experiments were conducted in the laboratory and 

 one small investigation has been carried out in a dehydrating 



