1921.] Wright—Chemical Technology of Meat Industry. 107 
In sheep and pigs the casing is principally the small intestine. After 
its remova] from the alimentary canal it is washed in water, and thereafter 
fermented in order to loosen the mucous lining of the intestine. This 
process is essentially bacterial in character. It is not possible to state 
definitely the identity of the micro-organisms concerned in this process, 
but mainly they are those which are responsible for the putrefaction of 
nitrogenous matter generally. The bacteria identified are those of the 
Proteus group, although the coliform group is also in evidence. The 
process is somewhat similar to that taking place during the puering of 
hides and skins. It is probable that further investigation will reveal the 
fact that enzyme action is a potent factor. Subsequently the intestines 
are scraped in order to remove the mucous and slime loosened by the 
fermenting process. They are then washed, covered with salt, bundled 
together, and finally resalted and packed in barrels for disposal. 
The preparation of the casings from cattle is somewhat different, being 
almost entirely a mechanical process, and this for the reason that while 
the narrowness of the sheep-intestine involves a bacterial decomposition 
in order to loosen the mucous it is possible in the case of that obtained 
from the cattle beast to turn it inside out in order to remove the slime 
and mucous membrane. After the removal of the mucous membiane, 
which in some places is carried out by a preliminary putrefactive process, 
the beef-casings are salted and packed in a manner similar to that adopted 
for those from sheep and pigs. 
The processes involved throughout the casing industry are important, 
and deserve more attention from the bacteriologist than they have 
received heretofore. The problems which arise, despite the apparently 
repellant nature of the inquiry, deserve the attention of the scientific 
attitude of mind ; for instance, the loss due to perforation, which, in 
spite of regrading into lengths of different measurement, means some¬ 
thing to the manufacturer, can readily be attributed to the fact that 
the processes of bacterial decomposition of the mucous membrane have 
proceeded so far that the true intestinal structure has been destroyed. 
It is thus clear that bacteriological control, as well as chemical, would aid 
the manufacturer in maintaining adequate supervision over this product. 
The presence of Bacillus prodigiosus in the cured product is revealed 
by the fact that a red coloration may be noticed in the material some time 
after curing. While this of itself is not a serious defect if it has not 
developed too far, there is definite evidence of imperfect curing. 
Literature cited. 
1-23. See list at end of Part I, p. 83. 
24. Thorpe, T. E., Tallow, Diet. Appl. Chem,., 1913. 
25. Collins, S. H., Chemical Fertilizers (Bailliere, Tindall, and Cox), 1920. 
26. Talbot, F. A., Millions from Waste (Fisher Unwin), 1919. 
27. Aston, B. C., N.Z. Journ. Agric., vol. 21, pp. 345-46, 1920. 
28. Leze, R., Utilisation des debris des animaux (Libraire des Sciences Agricoles), 1907. 
29. Moor, C. G., and Partridge, W., Bacteriology (Bailliere, Tindall, and Cox), 1916. 
30. Wright, A. M., J. Ind. and Eng. Chem. (New York), vol. 5, pp. 673-74, 1913. 
31. Wright, A. M., Applied Bacteriology, Lectures, Canterbury College, 1920 (not yet 
published). 
32. Fritsch, J., Manufacture of Chemical Manures (Scott, Greenwood, and Co.), 1911. 
33. Thorpe, T. E., Fertilizers, Diet. Appl. Chem., 1912. 
(To be continued.) 
