This product is largely derived from the nuclei of the leucocytes, which contain large quantities of the nucleo-proteids, of which uric acid is a decomposition product.
(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.
Research was thus directed towards ascertaining the nature of the toxic bodies in such a fluid, and Brieger and Fraenkel (1890) found that they were proteids, to which they gave the name " toxalbumins."
Though subsequent researches have on the whole confirmed these results, it is still a matter of dispute whether these proteids are the true toxins or merely contain the toxic bodies precipitated along with them.
To mention examples, blood serum solidified at a suitable temperature is a highly suitable medium, and various media are made with extract of meat as a basis, with the addition of gelatine or agar as solidifying agents and of non-coagulable proteids (commercial " pep tone ") to make up for proteids lost by coagulation in the preparation.