BUREAU OF CHEMISTRY. 435 



violet from a poor grade of the hexa methyl violet, and this may be 

 overcome. 



The actual result of the work so far accomplished is therefore 

 briefly as follows: Given 1 c. c. of a solution of any straight green, 

 brown, or violet dye, containing not more than 1 milligram and not 

 less than one-fifth milligram of such dye, the trees constructed 

 enable one to designate with absolute certainty the exact Green Table 

 niunber of said dye, with the following exceptions: (1) All browns 

 from G. T. No. 137 to 139, but not between 137 and 139, one against 

 the other; (2) all violets from G. T. No. 451 and 452, but not between 

 the two, one against the other. 



Similar trees will be worked out for the remaining colors — blue, 

 orange, yellow, and red — and the influence of mixed dyes tested, for 

 which work the fundamental material has already been collected. It 

 will also be necessary to determine what effect, if any, the food ma- 

 terial in which the dye is placed has upon the sensitiveness or relia- 

 bility of the trees as constructed. If this influence is disturbing, then 

 means of obtaining clean color solutions of the necessary strength 

 must be devised. 



The importance of this work in the enforcement of the food law is 

 apparent. Notwithstanding the number and variety of colors en- 

 countered the continuation of this systematic study will soon place 

 the matter on a practical working basis, the analytical trees furnish- 

 ing a rapid method of identifying the colors, further confirmatory 

 tests to be applied when deemed necessary. These studies are sup- 

 plemented by others at the New York and Seattle food-inspection 

 laboratories. 



Codfish. — Codfish and other salt fish are subject to spoilage during 

 the warm weather, particularly between the middle of June and 

 October, and a careful study has been made by Inspector Bitting of 

 the conditions surrounding the industry with a view to obviating or 

 reducing the loss from this source. The first evidence of spoilage is a 

 red discoloration, due to bacteria, and brown spots or " freckles," due 

 to a mold. The specific organisms causing the spoilage have been 

 determined and some of the conditions favorable to their growth 

 established. 



The preliminary work has been directed almost wholly toward 

 finding the cause of the spoilage and the source of the infection. It 

 has long been believed that the organisms causing the spoilage occur 

 normally in the localities where the fish are packed and are abundant 

 in the salt used for curing, possessing a tolerance for salt not common 

 to most germs. The extensive bacteriological studies on the causes of 

 reddening together with the inspection work present strong evidence 

 that the difficulty is largely due to factory infection, use of con- 

 taminated water for washing the fish, and careless methods of han- 

 dling, and that the influence of germs found in the lowlands, in the 

 vicinity of the factory, and in the salt seems to have been over- 

 estimated. At first it was believed that the problem consisted in 

 preventing spoilage in an infected product by stopping the growth of 

 organisms necessarily present, but these investigations indicate 

 strongly that it consists rather in the usual difficulty of preventing 

 infection. Recommendations along these lines have been made in 

 Bulletin No. 133, reporting the results of this investigation. 



