88 Transactions Tennessee Academy of Science. 



meat in a "liquid smoke" — a solution of crude pyroligneous acid, 

 and thus cut down the time from weeks to hours. Or they may 

 have on hand some meat that is getting old and is beginning to 

 show it; they can make it up into hamburger steak and with the 

 addition of a little sulphite not only keep it from spoiling but 

 brighten it up and make it look like fresh meat. 



As we all know, only a very small quantity of preservative is 

 necessary to accomplish the purpose sought, and such a quantity 

 may not be injurious in itself, at least for most of us. We are 

 not all alike, however. Some may have an idiosyncracy for that 

 particular substance ; others may have weak stomachs, their diges- 

 tion easily disturbed ; and there are invalids and infants to be 

 considered. All of these must be thought of as well as those who 

 are strong and healthy. 



Another argument against preservatives is that the use of some 

 of these substances, even though in small amount, but continued 

 for a long time, may finally produce deleterious effects, even in 

 a healthy person. If they are added to food the fact should be 

 plainly stated on the label. The consumer has the right to know 

 what he is buying. The label does not always tell the truth, 

 however, as regards the quantity, for often the preservative is 

 put in by a careless or ignorant workman and the amount is more 

 or less guess-work. 



There is one very efficient preservative which affects digestion 

 in an indirect way, or to state it differently, while it does not affect 

 some of the digestive ferments it does act upon the food, render- 

 ing it incapablj of being digested. This is formahlchyde. Some 

 years ago the writer carried on a series of experiments on the 

 action of formaldehyde upon these ferments and the food mate- 

 rials. The results may be briefly summarized as follows : 



Pepsin was dissolved in solutions of formaldehyde of (Hftcrent 

 strengths and these allowed to stand. After varying intervals 

 j)ortions were removed and the digestive activity tested. It was 

 found that ])ei)sin was not affected, even after standing in a four 

 per cent soluiion of formaldehyde for several weeks. lUood 

 fihrin was used in tliese tests, being the most suitable material 

 for tesling the activit\' of jicpsin ; it is also a very good rc]")rcsenta- 

 tive ol iiur ])r()U'i(l lood. hihrin was allowed to stand in solu- 

 tions of I'onnahk'luile of x-arxinij' streni'ths, and from time to 



