PUTREFACTION IN THE COMMONER FOOD FISH 99 



IX 



An Investigation into the Rate of Putrefaction in the 



Commoner Food Fish caught in and around 



Passamaquoddy Bay, N.B. 



BY 



Louis Gross,, M.D. 

 (Douglas Fellow in Pathology, McGill University, Montreal.) 



(With Plate). 



The present metliods of storing an^ shipping fish take little or no cognizance of 

 differences in the rate of putrefaction, a fact that is of considerable economic interest 

 and value. 



In the following investigation an effort was made to divide fish into groups which 

 represent their rate of putrefaction, and thus to determine different methods neces- 

 sary for handling the various fish. For example, fish which spoil readily would have 

 to be disposed of more quickly or else subjected to more careful storage, and vice 

 versa. 



Pursuing the method which I used to determine the relative rate of putrefaction of 

 eviscerated fish in which the gills are left and removed^, I proceeded to investigate 

 the comparative rate of spoiling of some of the commoner fish. 



The fish studied were: — 



Flounder, Pseudopleuronectes americanus (Walbaum). 



Hake, Urophycis chuss (Walbaum). 



Eel Pout, Zoarces anguillaris (Peck). 



Skate, Baja erinacea (Mitchill). * 



Cod, Gadus callarias, L. 



Sardine, Clupea Tvarengu-s, L. 



Haddock, Melanogrammus aeglifinus (L). 



Pollock, Pollachius virens (L). 



From each fish broth and agar was made according to the formula in the report 

 referred to above, the gills, mucus and meat being used. The broth was tnbed in 5 cc. 

 amounts and the agar for plating in 10 cc. amounts. 



As formerly, in order to retain the inherent titre of the fiish so that they might 

 resemble as closely as possible that of the recent condition, neutralization and" 

 standardization was not carried out. 



To determine how closely the titre of the media resembled that of a cold aquaeous 

 extract of the fish meat, and also to see whether the difference in rate of putrefaction 

 bore any relation to the Hydrogen Ion concentration, titrations were made of both. 

 (Table 1). 



The cold extract was made by triturating 50 gms. of fresh fish meat with 100 cc. 

 of distilled? water. This was allowed to stand for one hour and then filtered. The 

 figures given represent the amount of(N-lO) TTaOH necessary to neutralize the 

 acidity in 10 cc. of the extract or medium, phenolphthalein being used as the indicator. 



79550— 7J 



