Excerpt
PRESERVED MEATS AND MEAT-BISCUITS.
The many-headed public look out for 'nine days' wonders,' and speedily allow one wonder to obliterate the remembrance of that which preceded it. So it is with all newspaper topics, and so it has been in respect to the preserved-meat question. We all know how great was the excitement at the commencement of the present year on this matter. Ships' accounts overhauled; arctic stores re-examined; canisters opened and rejected; contracts inquired into; statements and counter-statements published; questionings of Admiralty officials in the two Houses of Parliament; reports published by committees; recommendations offered for future guidance; descriptions of the preserving processes at different establishments: all went the round of the newspapers, and then the topic was forgotten. It deserves to be held in remembrance, however, for the subject-matter is really important and valuable, in respect not only to the stores for shipping, but to the provisioning of large or small bodies of men under various exceptional circumstances.
A few of the simple laws of organic chemistry suffice to account for the speedy decay of dead animal substances, and for the methods whereby this decay is retarded or prevented. In organised substances, the chemical atoms combine in a very complex but unstable way; several such atoms group together to form a proximate principle, such as gluten, albumen, fibrin, &c.; and several of these combine to form a complete organic substance. The chemical rank-and-file, so to speak, form a battalion, and two or more battalions form the chemical army. But it is a law in chemistry, that the more complex a substance becomes, the less stable is its constitution, or the sooner is it affected by disturbing influences. Hence organic substances are more readily decomposed than inorganic. How striking, for instance, are the changes easily wrought in a few grains of barley! They contain a kind of starch or fecula; this starch, in the process of malting, becomes converted into a kind of sugar; and from this malt-sugar or transformed starch, may be obtained ale or beer, gin or whisky, and vinegar, by various processes of fermenting and distilling. The complex substance breaks up through very slight causes, and the simple elements readjust themselves into new groupings. The same occurs in animal as in vegetable substances, but still more rapidly, as the former are more intricate in composition than the latter, and are held together by a weaker tie.
What the 'vital principle' may be, neither chemists nor physiologists can tell us with any great degree of clearness; but it is this vital principle, whatever it may be, which prevents decay in a living organic substance, however complex. When life departs, the onslaught begins; the defender has been removed, and a number of assailants make their appearance. Air, heat, and moisture are the principal of these; they attack the dead organism, and gradually convert it into wholly different and inorganic compounds, such as water, carbonic acid, ammonia, phosphuretted hydrogen, and many others....