346 



Eev. W. H. Dallinger on 



[May 2, 



into the bulb A, carrying with it the fluid on the fragments of glass 

 which contained the just emitted spore. Thus it was known that 

 spores in the condition required were actually in the apparatus. 



The whole was now placed in a suitable vessel with solid white 

 paraffin, which was slowly melted, covering when in a fluid state the 

 whole bulb A. The heating of the paraffin was extremely gentle, and 

 it was raised as much above the boiling point of water as was con- 

 sistent with a gentle ebullition of the infusion A. This was continued 

 for ten minutes. The tube J was then hermetically closed before the 

 ebullition had ceased, and was removed from the paraffin and carefully 

 wiped while hot. The piece of platinum H was now shaken sharply 

 upon the septum F, and the calcined air contained in E was admitted 

 into the bulb A, the platinum remaining on the top of the passage Gr, 

 which was too small to admit of its entrance into A. In this way the 

 normal conditions of the infusion were as far as possible restored. 



The cell C was now fixed upon the stage of the microscope, and 

 could be carefully examined with the most suitable lenses ; and from 

 the fact that the cell was closed, " immersion " lenses could be em- 

 ployed, which gave an advantage in working. 



I first employed an immersion T Vth. But nothing was at all visible 

 but Brownian movement, and during the next seven hours no trace of 

 the organism could be found. The whole was now left for six hours 

 more, and then the entire cell was carefully " searched " with an im- 

 mersion y^th. At the close of an hour and a half three of the organ- 

 isms, one in the adult condition, and two in the semi-developed state 

 shown in fig. 24, were found swimming freely ; and in the course of 

 the next few hours the cell was freely visited by the organism in full 

 vigour. 



The length of time that elapsed before the organism appeared in 

 the cell, I presumed to be explicable by the fact, that it took a con- 

 siderable time for it to arise, in sufficient quantity, in the reservoir A 

 to render it probable that it would migrate into the cell C ; and this 

 supposition was sustained by subsequent facts. 



It was clear, then, that 212° F. was a temperature not destructive of 

 the germ when endured in a fluid condition. 



To reach higher temperatures it was, of course, needful to employ a 

 digester. For this purpose tubes alone were employed, which were 

 terminated in the cell C, fig. 26, but the bulb A and all its appendages 

 were dispensed with ; the tube D, for example, terminating at one end 

 in the delicate cell as before, but at the opposite end in the place 

 of A was a simple funnel for the delivery of the infusion into D. 

 When the spore in the required condition had been found and placed 

 in the funnel as before described, the fluid was inserted as before, and 

 the tube was then hermetically sealed. 



It was now placed in a small digester, with a register for pressures, 



