ON THE NATURE OF FERMENTATION. 189 



granules. It occurred to me that one cause of failure might be 

 this. Suppose one single group of such granules to exist, and 

 to become disturbed and broken up in the process of transference 

 to the glasses, it might vitiate the whole specimen of milk ; there- 

 fore, instead of drawing up the milk into the pipette with a 

 syringe and then expelling it, I determined to have it introduced 

 as directly as possible into the little glasses. With this object 

 I employed these two glass tubes, connected together, as you see, 

 with a short piece of india-rubber tubing, the wider tube being 

 for the purpose of receiving the milk, the narrower to conduct 

 it into the glasses. The glass tubes had been purified by a high 

 temperature, and the piece of india rubber connecting them, as 

 it would not bear a very high temperature, had been boiled for 

 half an hour. The same cow was taken out again into the open air, 

 and this day the elements were in my favour. It had been a 

 drizzly morning, and I might fairly hope that some of the 

 multitudes of organisms existing in the little orchard might 

 have been washed down and that the air might thus have been 

 somewhat purified. I was also more careful in this respect. I 

 got the dairywoman to milk the cow without drawing the hand 

 over the teat, performing the operation by an action of the fingers 

 in succession, so that the end of the teat should always be ex- 

 posed. Her hands were washed with water, and the cow's udder 

 also, and she having squirted out a little milk to wash away any 

 organisms from the orifice of the duct, the glass cap which pro- 

 tected the larger tube from dust was removed and the end of the 

 tube was held in the immediate vicinity of the teat ; a few 

 drachms were introduced, then the cap was readjusted, and then 

 these little glasses were filled by the simple expedient of alter- 

 nately relaxing and compressing with the finger and thumb on 

 the caoutchouc, so that there was as little disturbance as possible 

 of the organisms that might be supposed to be introduced in spite 

 of my care. It is six weeks since this was done. At first sight, 

 you might suppose, contrasting these appearances with those of 

 the other tubes which were charged only three days earlier, that the 

 milks of this last experiment were all pure. The truth is, aU 

 but two have organisms in them; but I may mention that all but 

 four had obviously organisms in them before I went for my trip 

 on the Continent three weeks ago. On my return I found that 

 in the course of the three weeks that had elapsed, two others had 

 gone; but they already showed organisms which, though very 

 pale and insignficant, were quite easily seen by a magnifier in 

 such considerable mass that I felt sure they must have already 

 been growing for a considerable time ; and, therefore, in all pro- 

 bability those that still seemed to the naked eye and to the 

 magnifier free from organisms were really so. Accordingly, two 



VOL. XVIII.-— NEW SER. N 



