MAINE SARDINE INDUSTRY. , 83 
years tobe covered with a white coating composed of stannic oxid, 
phosphoric acid, and iron. He attributed the corrosion to the action 
of phosphate and ammonia contained in the codfish and lobster. 
Determinations of the total amount of tin in packs of sardines in 
raustard sauce and of the tin content of mustard sauce, plain and 
fortrtied with acetic acid, when packed separately, showed that more 
ti was present in the fish and the sauce than in the sauce alone.’ 
This observation is in agreement with the conclusions drawn by 
Goss(10) who stated that the tin which is dissolved from the can 
forms an insoluble compound (by. adsorption) with the protein and 
carbohydrate (starch) elements of food. The active materials, acids 
or alkaline substances, responsible for the solution of the tin are then 
left free to dissolve more tin. This action may go on until no more 
tin can be taken out of solution by the food products within the CE, 
or until detinning is complete. 
It having been shown that diamine and monoamine are asso- 
ciated with ammonia and triamine, as constituents of the total vola- 
tile alkaline material formed in sardines (p. 75), solutions of all 
these amines were used to determine the extent of corrosion when 
present in sardime cans. The amine solutions, in approximately 
twentieth normal strength, prepared from Kahlbaum’s highest 
purity 33 per cent solutions, were introduced into the ordinary quarter 
oil cans. The interior of the cans and the lids were thoroughly 
cleaned by washing with alcohol and ether. The lids were then 
soldered on and the solutions introduced by means of a pipette 
through a tap and a vent hole in the end of the cans. As soon as the 
cans were filled, these holes were closed by a drop of solder. The 
cans were next processed for one hour in boiling water. One set was 
opened immediately after cooling and the others placed aside for 
future examination. The results of the determination of tin in the 
solutions after being removed from the cans, and the extent to which 
the inner surfaces of the cans were corroded are given in Table 36. 
—— 
1 Unpublished results on file in the Bureau of Chemistry. 
