110 INLAND FISHERIES. 



fish were then packed in ice, where they remained for two weeks. 

 When unpacked they were in ?l j^erf^ctly fresJi condition. 



It is evident, then, that this solution retards the initial stages of 

 putrefaction, even at summer temperatures, and for a sufficient 

 time for the fish to arrive at the markets, where they may be 

 iced and kept indefinitely. The solution of boric acid thus used 

 is not a preservative, and it is not intended as such, but, like soap, 

 is an agent of cleanliness. As the fish are simply sponged over, 

 the amount of the fluid that remains on a single fish is incon- 

 siderable, and careful analysis fails to show more than the least 

 trace in the flesh. Moreover, Chittenden and Gies have shown 

 that boric acid given in doses, even up to 3 gm. per da}^, has no 

 effect upon proteid metabolism, or on the nutrition of the body ; 

 that it is not cumulative, but is quickly eliminated from the system ; 

 and that it produces no renal complications. Its employment, 

 therefore, as above recommended, can have no injurious eftect on 

 the consumer. 



In preventing the growth of the micro-organisms which cause 

 putrefaction we also eliminate the cause of ptomaine formation. 

 Though some of the ptomaines are exceedingly poisonous, this is 

 not characteristic of all, and it can be safely stated that the greater 

 number of those that have been isolated are of a non-poisonous 

 nature. The kind of ptomain that is formed depends upon the sort 

 of micro-organism which produces it, the character of the material 

 acted upon, and the circumstances under which putrefaction takes 

 place. As the ptomaines are only transition products in the process 

 of putrefaction — mere temporary stages in the great process of de- 

 composition by which the complex organic molecule is trans- 

 formed into the simple inorganic state — it is evident that the kind 

 of ptomain present in putrid fish is dependent upon the stage of 

 putrefaction. The ptomaines formed when the putrefaction takes 

 place in free atmosphere will also be difterent from those resulting 

 from putrefaction Avhere atmosphere is excluded. At the present 

 time almost any illness caused from infected food is generally 

 spoken of as being due to " ptomain poisoning," In the majority 



