ALBUMEN.

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elevated temperature they undergo decomposition, which is accompanied bythe emission of fcetid gaseous products. That absolute absence of moistureprevents, to a great measure, that decay which is termed slow decompositionis instanced in the preservation of the bodies of the dead monks in the vaultof the church at the Kreuzberg, near Bonn; also of some bodies found in a vaultof the ancient church of St. Michel, at Bordeaux ; as well as by similareffects in the leaden vault of the principal church at Bremen, and in the vaultunder the choir of the church at Wienwert, a small village near Bolsward, inFriesland. While in proof that there is no decay at lower temperatures thano° C., may be cited the occurrence of the mammoths found in ice in Siberia ina state of perfect preservation. The hair, nails, hoofs, horn, and wool andsilk, resist' decomposition for a long period, the resistance being due partlyto the small quantity of water which they contain, and which can be expelledat ioo° C. (212 0 F.) According to M. Pasteur, this putrefaction, as it isgenetically termed, is due to the development of infusoria and vibrios, thegerms of which are conveyed by the air. Putrefaction may be entirely pre-vented, besides, by the actions already mentioned, by the exclusion of air, andby the destruction by means of heat of the pre-existent germs. Some sub-stances known as antiseptic possess the property of arresting and preventingdecay, and consequently putrefaction. Among such substances are themetallic compounds of copper, mercury, and arsenic; the sulphites andchlorides of sodium and potassium; and among organic substances tannin,carbolic acid, alcohol, &c. Gelatine, for instance glue, unless it is dry and ismaintained in a dry state, putrefies even more readily than albumen and fibrine.

The chemical composition of the albumenoid substances is very complex,and has not been completely elucidated. The composition cannot, therefore,be expressed by a rational formala. Mr. Hunt describes these substances ascompounds of carbohydrates (cellulose, sugar, &c.), with ammonia, less theelements of water. Messrs. Dusart, Schoonbrodt, P. Thenard, P. Schutzen-berger, and Guignet have obtained artificially nitrogenous substances, whichin many of their characteristics are similar to the nitrogenous substancesbelonging to the animal bodies. This was effected by causing ammonia toaCt upon sugar, cellulose, and similar substances at a temperature of 150° insealed tubes. Those substances often designated as epidermic, and also silk,a secreted matter, and the chondrogen tissues, behave in many respeCts similarlyto the albumenoid substances as regards the reactions with heat, alkalies,oxidising agents, nitric and hydrochloric acids, and nitrate of mercury.

Albumen.

Albumen is met with in the animal as well as in the vegetable kingdom ;in the former it is found in its normal state, and in solution, in the serumof blood, in the chyle and lymph, in all parenchymatous fluids, in muscle andbrain ; while the eggs of birds, the ova of reptiles and of fishes are composedchiefly of albumen. The albumen in nearly all these substances is combinedwith a larger or smaller quantity of an alkali, generally soda. Vegetablealbumen is not essentially different from that which occurs in the animalkingdom. The sap of all plants contains albumen, which occurs also in mostleguminous seeds, and largely in the fluids known as latex and cambium.All albuminous fluids from the vegetable kingdom exhibit in fresh state an