182 PHARMACEUTICAL BACTERIOLOGY. 



during the seasonal periods of plenty in order to tide over the periods of 

 scarcity. The very first observation made was that the accumulated and 

 stored food soon showed a tendency to undergo decomposition. The next 

 observation no doubt was that under certain conditions some organic food 

 kept better than under other conditions, thus, for example, primitive man 

 gradually learned that sun-dried meats did not decompose nearly as quickly 

 as undried meats. No doubt the value of smoking meats was soon ascer- 

 tained, in all probability purely accidentally, from meats, etc., which had 

 been exposed to the smoke of the camp fire. The preservative value of heat, 

 as in cooking and roasting, was noted. Next, no doubt the preservative 

 properties of certain chemicals used with foods, as ashes from the camp fire, 

 salt, brine, vinegar, wine (alcoholic beverages) and sugar was noted. Thus 

 primitive man made use of the germicidal powers of sunlight, drying, dry 

 heat, moist heat, wood ash, smoke, creosote (in smoking meats), salt solutions, 

 acids (in vinegar) and alcohol, without having any idea as to why 

 these agents retarded or prevented the decomposition of organic food 

 substances. 



In modern times the use of food preservatives is based upon th'e germ 

 theory of decomposition. The time-honored preservatives above referred 

 to have continued in use and many new ones have been added, as benzoic 

 acid, sodium benzoate, boracic acid, borax, salicylic acid, sodium sulphite, 

 sulphurous acid, formalin and many others. A somewhat generalized 

 theoretical assumption is that the chemical preservatives in foods are more 

 or less injurious to health. It cannot be denied that some of the preserva- 

 tives used are irritating to the kidneys and skin and some perhaps interfere 

 more or less with food digestion and assimilation. It has long been known, 

 for example, that the prolonged consumption of salted meats produces serious 

 skin affections designated as scurvy. The sulphites are irritating to the kid- 

 neys; formalin interferes with digestion of foods, etc. However, there can be 

 little doubt that in the comparative sense it is far more conducive to health 

 and longevity to eat preserved foods than foods which are more or less 

 decomposed. We are daily making use of foods which contain small 

 quantities of natural preservatives. Cranberries, for example, contain 

 benzoic acid; formalin and phloroglucin are present in minute quantities in 

 certain plants; a multitudinous variety of salts, acids, sugars, aromatic oils, 

 etc., are present in food plants. Food chemists do not appear to be seriously 

 worried about these natural preserving agents nor about the old-time artificial 

 preservatives as smoke creosote, salt, brine, sugar, and vinegar, and it is 

 reasonable to suppose that careful investigation will disclose new chemical 

 preservatives which are superior to those mentioned. The whole discussion 

 regarding artificially added chemical food preservatives will no doubt sim- 

 mer down to the following: What is the smallest amount of the least objec~ 



