1873.] necessary to kill Bacteria, Vibriones, fyc. 229 



muslin, were boiled for about ten or fifteen minutes, and then whilst 

 boiling strained through ordinary Swedish filtering-paper into a glass 

 beaker which had previously been well rinsed with boiling water. A 

 number of glass bottles or tubes were also prepared, which, together 

 with their stoppers or corks, had been boiled in ordinary tap water for 

 a few minutes*. They were taken out full of the boiling fluid ; and the 

 stoppers or corks being at once inserted, the vessels and their contents 

 were set aside to cool. "When the filtered infusion of hay or turnip 

 had been rapidly cooled down to about 110° F. (by letting the beaker 

 containing it stand in a large basin of cold water), it was inoculated 

 with some of a turbid infusion of hay swarming with active Bacteria 

 and Vibrioncs — in the proportion of one drop of the turbid fluid to each 

 fluid ounce of the now clear filtered infusionf. The beaker was then 

 placed upon a sand-bath, and its contained fluid (in which a thermometer 

 was immersed) gradually raised to the required temperature. The fluid 

 was maintained at the same temperature for five minutes by alternately 

 raising the beaker from and replacing it upon the sand-bath. The bottles 

 to be used were then one by one uncorked, emptied, and refilled to the 

 brim with the heated inoculated fluids . The corks or stoppers were at 

 once very tightly pressed down, so as to leave no air between them and 

 the surface of the fluids. The beaker was then replaced upon the sand- 

 bath and the gas turned on more fully, in order that the experimental 

 fluid might be rapidly raised to a temperature 9° F. (5° C.) higher than 

 it had been before. After five minutes' exposure to this temperature 

 other bottles were filled in the same manner, and so on for the various 

 temperatures the influence of which it was desired to test. 



Thus prepared, the bottles and tubes have been exposed during the day 

 to a temperature ranging from 65° to 75° F. And generally one had 

 not to wait long in order to ascertain what the results were to be. In 

 some cases, if the contents of the vessels were to become turbid, this 

 was more or less manifest after an interval of forty-eight hours ; in 

 other cases, however, the turbidity manifested itself three or more days 

 later : the reason of this difference will be fully discussed in a subsequent 

 communication. 



For the sake of simplicity and brevity, the necessary particulars con- 

 cerning the 102 experiments have been embodied in the following Table : — 



* The vessels employed have varied in capacity from two drachms to four ounces ; 

 some have heen provided with glass stoppers and others with very tightly fitting corks ; 

 and the latter I find have answered quite as well as the former. On the whole I have 

 found tightly corked one-ounce phials to be about the most convenient vessels to employ 

 in these inoculation experiments. 



f It was found desirable to filter the infusions after they had been boiled, because 

 the boiling generally somewhat impaired their clearness. 



% At this stage, of course, very great care is needed in order to avoid all chance of 

 accidental contamination either with living organisms or with unheated fragments or 

 particles of organic matter. 



