Avri, against, and vrJIrrucos, putrefactive), the name given to substances which are used for the prevention of bacterial development in animal or vegetable matter.
Exudations and Rotting.The outward symptoms of many diseases consist in excessive discharges of moisture, often accompanied by bursting of over-turgid cells, and eventually by putrefactive changes.
In the interior of the grape, in the healthy blood, no such germs exist; crush the grape, wound the flesh, and expose them to the ordinary air, then changes, either fermentative or putrefactive, run their course.
When exposed to air the latex gradually undergoes putrefactive changes accompanied by coagulation of the caoutchouc. The addition of a small quantity of ammonia or of formalin to some latices usually has the effect of preserving them for a considerable time.
Nevertheless, gangrene is nothing more or less than the putrefactive fermentation of an animal tissue still attached to the body.
If the dead part be protected from the ingress of putrefactive organisms, however, it separates from that which is living without the ordinary evidences of gangrene, and is then known as an " aseptic slough."
The steps in the breaking down of the highly complex nitrogenous proteid compounds contained in the humus of the soil, or applied to the latter by the farmer in the form of dung and organic refuse generally, are many and varied; most frequently the insoluble proteids are changed by various kinds of putrefactive bacteria into soluble proteids (peptones, &c.), these into simpler amido-bodies, and these again sooner or later into compounds of ammonia.
They are of importance, since the higher homologues are identical in many cases with the ptomaines produced by the putrefactive action of some bacteria on albumen and other related substances.
Bring organic material to the putrefactive state - or saprophilous, i.e.
The combined nitrogen of dead organisms, broken down to ammonia by putrefactive bacteria, the ammonia of urea and the results of the fixation of free nitrogen, together with traces of nitrogen salts due to meteoric activity, are thus seen to undergo various vicissitudes in the soil, rivers and surface of the globe generally.
We have thus an explanation of the occurrence of marsh gas and sulphuretted hydrogen in bogs, and it is highly probable that the existence of these gases in the intestines of herbivorous animals is due to similar putrefactive changes in the undigested cellulose remains.
(c X 600;) al X 1500, above.) (From Fischer's Vorlesungen uber Bakterien.) into the higher plants as sulphates, built up into proteids, decomposed by putrefactive bacteria and yielding SH 2 which the sulphur bacteria oxidize; the resulting sulphur is then again oxidized to SO 3 and again combined with calcium to gypsum, the cycle being thus complete.