302 PHENOMENA OF PUTREFACTION. 



an analysis by Volker, the juice collecting in the cups of Nepenthes 

 contains about 0.8-0.9 P er 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 albumin contains a poisonous fission product which 

 cannot be destroyed by boiling, treatment with alcohol, or similar 

 methods, and is consequently not an organised creature, but a 

 chemical compound (known as "extractive putrescent poison"). 

 This discovery, which was tested and confirmed by M. HEMMER (I.) 

 and F. SCHWENINGER (L), 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 them- 

 selves 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. 

 BERGMANN (I.) and 0. SCHMTEDEBERG (I.) chiefly deserve mention 

 as being the first to obtain (in 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 avail- 

 able for closer chemical investigation and characterisation. M. VON 

 NENCKI (V.) was the first, in 1876, to successfully prepare such a 

 poison in the pure state, viz., the alkaloid collidine (isolated from 

 putrid albumin), having the formula C 8 H 11 N, and being (accord- 

 ing to its constitution) trimethyl pyridine, C 5 H 2 N.(CH 3 ) 3 . Such 



