1888.] Dr Woodhead on Mercuric Scclts ccs Antiseptics. 247 
that, under these conditions, all the albumen in the cultivation 
medium would be coagulated immediately, and would so remain, 
for there is an excess of the mercury salt, not of the albumen. 
In such a case it is quite possible that there is actually a 
coating or pellicle of albuminate of mercury formed at an early 
stage around the spores or micro-organisms which, protecting 
them against the action of the added sublimate solution, is only 
dissolved when the organisms with their pellicles are again intro- 
duced into a nutrient fluid in which, of course, there is sufficient 
albumen to form an excess, and so to dissolve the pellicle and set 
the organism free to flourish in its new surroundings. If the 
inoculation be made into gelatine, the solid mass does not yield the 
excess of albumen so readily, and the slight quantity of mercury 
remaining in position around the organism prevents its development. 
In the blood of an animal there are, of course, the same conditions 
that are present in a fluid medium, as regards the presence of 
albumen and its action as a solvent of the albuminate. 
In the case of the biniodide of mercury, we could have no such 
fallacy creeping in, as no insoluble compound is formed, and the 
whole of the mercuric salt acts directly on the micro-organism. 
As the result of the experiments of numerous workers, it may be 
concluded that all the mercuric salts which can be kept stable, and 
in solution.^ have powerful antiseptic or germicidal properties, 
varying (a) according to the quantity of mercury they contain, and 
(&) according to the acid or halogen with which they combine 
(a somewhat important factor). If the bichloride be used, it readily 
unites with albumen. When used as a lotion in surgical cases, 
this must often prove a serious drawback in cases of profuse 
h^emorrhage, one part of blood being sufficient to neutralise the 
antiseptic power of ten parts of the 1 to 1000 sublimate solution, 
twenty parts of the 1 to 2000 solution, and so on in proportion. 
We are then using an aseptic, but not an antiseptic solution. In 
certain cases this is doubtless an advantage, but in many cases it is 
a source of danger. The biniodide does not unite with the albumen, 
hence the whole of its antiseptic power is available at the time, and 
so continues as long as it remains in contact with the tissues. 
As we have seen, the whole of the mercury in the bichloride 
solution may be rendered available by adding common salt or 
