1030 FOODS AND FOOD ADULTERANTS. 



ing bacteria, the presence of an extremely small amount of a germicide 

 like salicylic acid suffices to restrain all further fermentation, although 

 the amount of antiseptic added might not have been sufficient to mate- 

 rially affect bacterial life if added to a solution in an active state of 

 decomposition. Most of the bacteria commonly found will not resist a 

 temperature of 65 to 70 when in the active state in a fermenting 

 liquid, but these bacteria in the condition in which they are found in 

 dust, or when in the shape of spores, resist this heat pretty well. If, 

 however, the liquid in which these desiccated bacteria or spores occur 

 contains a minimal amount of salicylic acid or other antiseptic, devel- 

 opment into the vegetating form does not occur. Now, in exposing a 

 can of food to the action of heat, no matter how conveyed, it is always 

 a matter of difficulty to insure that the central portion of the contents 

 of the can shall receive as much heat as the portions lying next the 

 surface, and this is particularly true of solid-packed goods, such as 

 corn and baked beans. It can be done in time, of course, but time is 

 expensive. Dosing a food with a cheap antiseptic saves time and trou- 

 ble and enables the canner to be quite certain of the keeping qualities 

 of his goods, no matter in how slovenly or sloppy a manner his work may 

 have been conducted. For this reason antiseptics are daily growing in 

 favor among the preservers. 



One objection to the use of chemical preservatives arises from the 

 fact that they do not confine their anti-fermentative action to the food 

 in the can, but continue to exercise it after the food reaches the stomach, 

 which is riot desirable. Digestion is effected by the action of unor- 

 ganized ferments to a large extent, and on this action most antiseptics 

 have a greater or less restraint. 



It is difficult to say how far the use of preservatives cheapens canned 

 goods. Of course all saving of labor or time tends to lessen the cost of 

 production, but there seems to be no material difference in point of cost 

 to the consumer between those brands of canned goods which contain 

 antiseptics and those which do not. Probably were the use of preserv- 

 atives discontinued there would be no material change in the retail 

 price. 



In the work done on the canned vegetables but two preservatives 

 were found, if salt be disregarded, viz, salicylic and sulphurous acids. 

 Salt is supposed to be added primarily as a condiment, and only secon- 

 darily as an antiseptic. It was present, however, in some cases in inor- 

 dinate quantities. In one case (No. 10923) it constituted 40 per cent of 

 the dry matter. Salicylic acid was found in 47. per cent of the total 

 samples examined. Sulphurous acid was also very common. 



METHOD FOR DETECTION OF PRESERVATIVES. 



Iii the method 1 adopted for preservatives, the contents of the can 



1 Thin scheme is based in part on one proposed liy Hie late I. T. Davis in an unpub- 

 lished paper on meat preservatives. 



