A simpler method of preserving animal food For sea-stores is the following :—the meat is nit into slices of four to eight ounces, steeped For five minutes in a vessel of boiling water, ind dried on a network at a temperature of 'bout 120° Fahrenheit. The liquid or soup 7ormed by steeping the meat is next evapo rated to the state of a thick varnish, to which t little spice is added. The dry pieces of meat tre dipped into this gravy, and dried again ; mud this dipping and drying are repeated two >r three times. The meat will in this dry tate remain good for a year or two ; and must hen be cooked in the usual way by boiling, The natural methods of preserving organized ;ubstances are few and simple : the artificial nore numerous, as well as more complex. Chey consist either in causing such changes n the elementary constitution of a body as hall form a new and less destructible article, u. in introducing some additional principle vhich shall hinder the exercise of the natural endency of the substance to decomposition. The first set of means constitute the various inds of fermentation, with respect to which ye may remark, that the products of them are lot only little disposed to undergo decompo ition, but have also a powerful effect in pre enting other substances from undergoing it ; he most remarkable of these are acetic acid, or vinegar, and alcohol. The formation of sugar, another product of fermentation, is a powerful means of preserving fruits, in which it is formed spontaneously, or to which it is afterwards added. The addition of sugar is practised in forming syrups, jellies, and pre serves.
Those parts of plants which contain much carbon last the longest. In trees cut down and exposed to air and moisture, the bark, which contains most carbon, endures after the rest has perished. The seed also contains
much carbon, and when seeds are sent from India to England they are always wrapped in recently prepared charcoal. When stakes or piles of wood are to be driven into the beds of rivers or marshes, they are previously charred ; and to preserve water sent to sea, the inner side of the cask is also charred.
There are many substances which when added to animal matter prevent for a longer or shorter time their decomposition, such as saltpetre (nitrate of potass), and common salt (chloride of sodium), which last is supposed to act by abstracting the elements of water ; certain it is that meat is rendered by salting much drier, harder, less easily digested, and consequently less nourishing. Many aroma tic substances have a similar power of pre venting putrefaction for a time. They were extensively employed in embalming in ancient as well as modern times, as the Egyptian mummies prove. Oils and resinous substances long resist putrefaction, and preserve other substances from it ; bitumen, naphtha, and empyreumatic oils, are examples of this. Ens sia leather, which is dressed with the empy reumatic oil of the birch, not only does not become mouldy, but also preserves the books which are bound with it. The process of de composition is greatly hastened by the agency of fungi, such as those which cause mouldiness, and the more formidable destroyers which occasion the dry-rot. The fungi which cause mouldiness are generally prevented from de veloping themselves by the presence of some aromatic oil ; and the others which occasion the dry-rot in timber, may be prevented from developing themselves by the process invented by the late Mr. Kyan. [DRY-RoT.]