232 THE PHENOMENA OF PUTREFACTION 



1890, in his experiments on the contents of the urns of Nepenthes ; and two 

 years later the matter was again examined by TISCHUTKIN (II.) in the following 

 plants: Drosera rolundifolia, L., D. Longifoli't, L., Dioncea muscipula, Ell., 

 Nepenthes Mastersi, the results confirming the hypothesis expressed above, viz., 

 that the digestion of the albuminoid bodies falling or introduced into the juice 

 excreted by these plants is exclusively due to the activity of bacteria settling in 

 the said liquid and there producing a proteolytic enzyme. According to an 

 analysis by Volker, the juice collecting in the cups of Nepenthes contains about 

 0.8-0.9 per cent, of dry matter, about 39 per cent, of which consists of malic 

 acid and 50 per cent, of potassium chloride, i.e. the two substances already 

 mentioned in 41 as powerful bacterium stimulants. The juice in the unopened 

 young cups of Nepenthes contains neither proteolytic enzyme nor bacteria, the 

 latter falling out of the air into the liquid only after the cups are opened. 

 Ample opportunity is soon afforded for the exertion of their decomposing power 

 on the insects caught in these traps and prevented by special contrivances from 

 escaping. For the preparation of this nutrient material the organisms elaborate 

 enzymes, the proteolytic properties of which are utilised by the plant. These 

 so-called carnivorous plants consequently present a beautiful example of 

 symbiosis existing between higher plants and bacteria. 



171. Ptomaines and Leucomaines. 



The first step towards the elucidation of the regrettable fact that putrefying 

 albuminoids, when introduced into the blood-vessels of man or the higher 

 animals, set up violent reactions (sepsis, septiccemia), which may, under certain 

 circumstances, prove fatal, was made by P. L. PANUM (I.) in 1856, who proved 

 that putrescent albumen contains a poisonous fission product which cannot be 

 destroyed by boiling, treatment with alcohol, or similar methods, and is con- 

 sequently not an organised creature, but a chemical compound (known as 

 " extractive putrescent poison "). This discovery, which was tested and con- 

 firmed by M. HEMMER (I.) and F. SCHWENINGER (I.), is also of historical 

 importance in Pathological Bacteriology, since thenceforward medical views and 

 researches concerning the nature of the diseases engendered by bacteria pursued 

 two divergent paths : the one school holding these diseases to be toxic phenomena 

 produced by the poisonous metabolic products (toxins) of parasites growing 

 within the body, whilst the other regarded the vital activity of the organisms 

 themselves as the immediate cause of the malady. There is no occasion for us 

 to follow this conflict of opinions, which is still rife ; so we may confine our 

 attention to the efforts of Panum's successors in the narrower field of albuminoid 

 putrefaction. Among these E. BEIIGMANN (I.) and 0. SCHMIEDEBERG (I.) chiefly 

 deserve mention as being the first to obtain (1868) a poison of this group by 

 precipitation as sulphate (the so-called sepsin sulphate) from putrescent beer- 

 yeast in a crystalline form, and therefore available for closer chemical investi- 

 gation and characterisation. M. VON NENCKI (V.) was the first, in 1876, to 

 successfully prepare such a poison in the pure state, viz., the alkaloid collid'.ne 

 (isolated from putrid albumen), having the formula C 8 H,,N, and being (accord- 

 ing to its constitution) trimethyl pyridine, C 5 H,N. (CH 3 ) 3 . Such alkaloids, are 

 also formed, as a matter of course, during the decomposition of the human 

 cadaver (Gr. ptoma), and on this account F. SELMI (II.) in 1878 gave the name 

 ptomaines to putrefaction alkaloids in general. 



This newly discovered group was gradually enlarged, and now includes more 

 than fifty substances. Comparatively speaking, the majority of these new bodies 

 were discovered by L. BRIEGEH (III.), to whom we are also indebted for new 

 methods for the separation of these poisons from putrescent liquids. Of the 



