AND ITS BEARINGS ON PATHOLOGY 365 
introduced into each glass, the result will probably be that fermentative changes 
of totally different kinds will occur in the various glasses, as indicated by striking 
differences of colour in the contained milk and differences of odour in the air 
in the glass shades ; and, what is extremely interesting, some 
glasses will escape all change. This last fact proves at once 
the important truth that the fermentative agency in water, 
the existence of which was pointed out long ago by Dr. 
Burdon-Sanderson, is not matter dissolved in the water, but 
consists of insoluble particles of some kind or other suspended 
init. For if the ferment were dissolved in the water, every 
equal-sized drop would produce an equal effect. But the 
fact is, as already stated, that when drops of such minute- 
ness are employed, some of the inoculated glasses escape 
altogether, and those which are affected exhibit different 
kinds of fermentation, and we thus learn from this simple 
experiment not only the truth that the fermentative material 
is in the form of insoluble particles, but that every minim 
of ordinary water contains several different kinds of fer- 
ments, which, though generally confused through being 
mixed up together, declare their individual peculiarities 
when isolated by this method of separation. 
These various fermentative changes were -invariably 
found associated with bacteria, those in different glasses 
sometimes showing themselves conspicuously different under 
the microscope, though often only distinguished by their 
effects. Thus, in one case, the cream being particularly thick, 
a bright vermilion-coloured point appeared after some 
gum copal brought to a liquid state by a high temperature and then applied to 
the objects to be cemented, which have previously been heated to an equally 
high degree. The presence of an air-bubble in the water within the syringe 
would also by its elasticity vitiate accuracy of performance. This is got rid 
of, so far as the body of the syringe is concerned, by first accurately charging 
it with water that has been boiled to dispel its dissolved air. The water of 
inoculation, with which the glass nozzle is to be filled, is also raised to a 
somewhat higher temperature than the air of the apartment by placing the 
vessel containing it before the fire for a few minutes. The nozzle with its Fic. 8. 
adapter is purified by boiling it in water in a saucepan for about half an hour, 
after which its fine end is immersed in the water for inoculation, and when 
it is filled beyond the bend the other end is depressed, so that the rest of the filling may be done by 
syphon action. When a drop of water projects from the adapter, it is applied to a correspondingly 
projecting drop of water at the mouth of the syringe, and the two drops coalescing prevent the in- 
troduction of a particle of air when the nozzle is screwed on. With these precautions drops of exactly 
the same size can be ensured. 
