1889 — 90 .] Dr Griffiths on Researches on Micro-Organisms. 269 
XL Soluble Ferments produced by Microbes. 
Professor Giglioli ( Fermenti e Microbi) describes the production 
of soluble ferments by living micro-organisms. What have the 
soluble or non-organised ferments (produced by pathogenic microbes) 
to do with contagious diseases ? Before the formation of alkaloids, 
is a soluble ferment excreted by each microbe 1 Is it possible that 
the ferment causes the chemical disintegration of albuminoid 
molecules with the ultimate formation of alkaloids ? 
We know that vegetable diastase (produced in the first instance 
from albumin by the action of living cells) is capable of converting 
starch into dextrose, and cane-sugar into dextrose and levulose : — 
(a) C 6 H 10 O 5 4- H 2 0 = C 6 H 12 0 6 . 
(b) C 12 H 22 O n + h 2 o = c 6 h 12 o 6 + c 6 h 12 o 6 . 
These substances are of a definite chemical composition and 
formed by the action of non-organised ferments. Therefore, may 
we not infer that the alkaloids of disease are possibly produced by 
the soluble ferments secreted by pathogenic microbes. 
The researches of Giglioli {Fermenti e Microbi ) and Schiavuzzi 
{Atti della R. Accademia dei Lincei , 1886) have thrown consider- 
able light on this all-important but most obscure subject. 
Recently, N. Kravkoff {Journal of the Russian Physico-Chemical 
Society , vol. xx. [part 8], pp. 623 — 632) has made a thorough 
inquiry into the properties and action of pure vegetable diastase. 
The production of alkaloids by pathogenic microbes is most 
important ; for “ one of the most interesting facts observed in the 
growth of septic micro-organisms is this, that the products 
of the decomposition started and maintained by them have a 
most detrimental influence on themselves, inhibiting their power of 
multiplication ; in fact, after a certain amount of these products has 
accumulated, the organisms become arrested in their growth, and 
finally may be altogether killed. Thus the substances belonging to 
the aromatic series, — indol, skatol, phenol, and others which are 
produced in the course of putrefaction of proteids, — have a most 
detrimental influence on the life of many micro-organisms, as has 
been shown by Wernich and others” {Klein). 
Quoting from Part II. of this paper : — “ If the soluble zymases 
