1887.] Dr A. B. Griffiths on Micro-Organisms. 103 
sixteen days. Therefore, I conclude that the said acid has acted 
upon this organism in a similar manner to those already mentioned. 
8. Protococcus vulgaris and Protococcus pluvialis (fig. 4). 
These two species of Protococcus are 7iot acted upon by the solu- 
tion of salicylic acid, and a much stronger solution of the acid has 
no effect upon them. It appears that there is a difference in the 
Protococcus 
vulgaris. 
Fig. 4. 
atomic structure of the cellulose forming the cell-walls of these two 
species of Protococcus and the various micro-organisms alluded to 
in this paper; that is, the cellulose of Protococcus is more like 
the cellulose of the higher forms of plant life, which is not acted 
upon by the acid in question. 
So far, we have seen that salicylic is an antiseptic agent, capable 
of attacking or acting upon their cellulose walls. 
This acid, and acids generally, appear adverse to the life-histories 
of certain micro-organisms. It will he remembered that M. Boche- 
fontaine swallowed secretions from choleraic patients containing 
Comma bacilli , made up in the form of pills, without any serious 
consequences. There is no doubt the acid properties of the gastric 
juice in the stomach had acted upon these micro-organisms in some 
way or other, and so prevented them living their life-histories in 
the intestine. 
The practical outcome of this piece of research (although far from 
