IMPROVEMENTS IN PREPARING FISH FOR SHIPMENT. 
235 
of cases the poisonous bacterial products are not basic, though their true chemical 
structure is not understood. 
It is worthy of note in this connection that poisonous ptomaines do not begin to 
appear until about the seventh day of putrefaction, and that they finally disappear if 
putrefaction is allowed to go on for a considerable time. The toxicity of the ptomaines 
themselves is not affected by cooking, no matter how thorough this may be. It should 
also be noted that there are two distinct kinds of poisoning that may arise from the 
use of fish as food. The first is an intoxication caused by the devouring of meat which 
has become invaded by ptomaine-producing bacteria. The second is an iutoxication 
brought about by fish not necessarily infected with bacteria, but in which the poisons 
are leucomaines produced by the tissues of the fish and their normal product. 
The researches of Meisener, Eosenbach, G. Hauser, F. Jahu, J. von Toder, and 
others have shown that the blood and flesh of healthy animals are entirely free from 
bacteria. But the coutents of the digestive organs are rich in schizomycetes. Popoff 
has shown that the digestive canal of a healthy new-born animal is, at the moment of 
birth, free from bacteria. These, however, subsequently obtain access, principally in 
the food, and the contents of the bowels become extremely rich in microbes. 
If a slaughtered animal is left without being disemboweled, these bacteria will make 
their way from the alimentary tract through the capillary vessels of the intestinal 
villi into the arterioles, the alkaline coutents of which (rich in albumen) are especially 
favorable to these acidly putrefactive bacteria, so that the entire carcass quickly 
begins to undergo decomposition. This early decay may be prevented by the imme- 
diate removal of the entire alimentary canal, from esophagus to rectum, and if this 
precaution is taken the flesh (as already shown) will for a time remain free from 
putrefactive bacteria. If putrefaction afterwards sets in, it is probably due to bacteria 
from external sources which have obtained access to the flesh. 
The gradual penetration of bacteria by way of the blood vessels into the interior 
of the flesh has been studied by Trombetta and Gartner. Gartner found them in the 
external layers only of meat 3 days old, but at the end of 7 days they had penetrated 
2 cm. below the surface. It is probable, however, that the flesh of fish is not so resist- 
ant to the penetration of bacteria. The sources of this bactei’ial infection can not be 
entirely removed, but they can be considerably reduced by cleanly procedure, as 
above recommended, and attempts may be made to restrict the increase of the microbes 
and thus arrest the process of decay. The most common remedy is cold, but experi- 
ment has shown that the temperature must be kept some degrees below freezing to 
obtain the best results. This method is used not only in the American and Australian 
abattoirs, but haddock caught in Norway are cleaned and frozen at — 50° C. and then 
shipped in specially constructed steamers. This freezing of fish does not immediately 
kill the bacteria present, for Koch has found very many bacteria in fish treated in this 
way, but it prevents the reproduction of the bacteria for the time being. 
Foster has found that certain germs increase in meat stored at moderately low 
temperatures, though actual putrefaction is not produced by them. Moreover, the 
researches of Frrenkel, Bordoin, Uffreduzzi, Prudden, and Heyroth show us that 
natural ice may contain both putrefactive and pathogenic bacteria. This fact alone 
should teach us to look with suspicion upon any meat that has been brought in direct 
contact with ice of unknown origin, especially when the ice is allowed to melt so that 
the drip soaks into the flesh. 
