48 Proceedings of Royal Society of Edinburgh. [dec, 5, 
bed was prepared for tbe poison, by whose action the population 
was ensured against barm from any specific germs that by accident 
or other cause might find their way into the drains or sewers of 
the town. The sulphate of iron in the drain, thus lying in waiting 
for the poison, may be likened to the wire gauze of the Davy lamp, 
always at hand to prevent the explosion of the fatal fire-damp.”* 
I have shown {Chemical News, vol. xlix. p. 279 ; vol. liii. p. 
255 ; vol. Iv. p. 276 ; Journal Chemical Society [Trans.], 1886, 
p. 119 ; and Cliemiker-Zeitung^ No. 47) that ferrous sulphate 
destroys parasitic fungi ; and it is probable that on a large scale 
(for sewers, &c.) it would form a cheap and powerful disenfectant 
against epidemic diseases in general. 
IX. Soluble Zymases and their Microbes. 
What have the soluble zymases (ferments) produced by various 
pathogenic microbes to do, in connection with contagious diseases ? 
Arc they the cause of the disease directly or indirectly 1 By their 
chemical disintegration, do they form the alkaloids (ptomaines) 
found in disease ? These problems require our earnest attention. 
Dr Schiavuzzi of Pola (Istria in Austria] {Rendiconti della R. 
Accademia dei Lincei, December 1886) has confirmed Kleb’s and 
Tommasi-Crudeli’sf discovery of Bacillus malarix, and that it is 
the real cause (directly or indirectly) of malarial fever. Schiavuzzi 
also finds that in the blood of animals infected with the disease, 
the red corpuscles undergo similar alterations as Marchiafava and 
Celli {Fortschr. d. Med., vol. iii.) have shown to be characteristic 
of malarial fever; and he considers these changes in the blood 
corpuscles to be caused by a “pathological” ferment of a different 
nature to Bacillus malarise. Most probably a soluble zymase 
secreted by the microbe itself. Professor Giglioli, in his recent 
work Fermenti e Microbi, describes the production of soluble fer- 
ments by micro-organisms. 
If the soluble zymases produced by living pathogenic microbes 
* The Cholera Microbe, and how to Meet it, by Sir C, .Cameron, LL.D., 
M.P., &c., p. 25. 
t Archiv fur Experimental Pathol., 1879 ; and also Tonimasi-Crudeli’s 
memoir, “ Der in Erdboden von Seliunte imd Campobello,” 
Archiv fiir Exp. Pathol., 1880. 
