218 THE FLOATING-MATTER OF THE AIR. 



at right angles above the plug, and a portion of it was 

 drawn out to a tube of capillary diameter, represented 

 at o. The end a was connected with the Sprengel 

 pump, and after the exhaustion had been continued for 

 the required interval, the neck of the bulb was sealed 

 at o. 



On the 14th of March three bulbs charged with 

 turnip-infusion, from which the air had been as far as 

 possible removed by the ordinary air-pump, were con- 

 nected with the Sprengel, which continued the exhaus- 

 tion uninterruptedly for three hours. The air dissolved 

 in the liquid freely escaped from it at first, and it con- 

 tinued to appear in minute bubbles long after the 

 exhaustion had reached a considerable degree of perfec- 

 tion. The drawn-out necks of the bulbs being hermetic- 

 ally sealed, the infusion within them was maintained 

 as before for ten minutes at the boiling temperature. 



It will be remembered that when the infusion and 

 the air above it possessed their ordinary supply of oxy- 

 gen, 180 minutes' boiling failed to sterilize the turnip- 

 infusion. Here, when the air was withdrawn from the 

 liquid, exposure for one-eighteenth of the foregoing 

 interval sufficed to produce perfect barrenness. The 

 infusion in the three bulbs here operated on remains to 

 the present hour clear in body and perfectly free from 

 scum. 



On the 15th of March seven bidbs charged with in- 

 fusion of turnip were treated in the manner just de- 

 scribed, being purged of their air by thi'ce hours' action 

 of the Sprengel pump, and boiled for ten minutes after- 

 wards. Six out of the seven remain perfectly pellucid. 



On the 16th of March the result was still further 

 verified. Seven bidbs were then charged with turnip- 

 infusion, exhausted first by the air-pump, and afterwards 

 by five hours' action of the Sprengel pump. Hermetic- 



