58 ON THE ANTISEPTIC SYSTEM 



of the liquid. [The facts subsequently ascertained, of the absence of any living 

 organism which the microscope could detect in the liquid from one of the flasks 

 with bent neck, and the speedy appearance of abundance of such minute objects 

 as well as of others visible to the naked eye, when the liquid had been removed 

 from its protecting chamber, afford, of course, most satisfactory confirmation.] 

 There is one circumstance in this experiment which may appear difficult 

 to comprehend. Admitting that the angles of a narrow bent tube might arrest 

 the progress of even the finest dust of air w^hen in very gentle motion, is it con- 

 ceivable that such particles could fail to be driven into the flasks during the 

 first rush of air into them on the withdrawal of the lamp at the time of the 

 original boiling ? This difficulty is met by Pasteur in the following way. He 

 says doubtless germs are carried in, but they pass into a liquid so hot as at 

 once to destroy their vitality. Now, though I feel much diffidence in expressing 

 dissent from so high an authority, I must say I do not feel satisfied with this 

 explanation ; inasmuch as Pasteur has himself related experiments which show 

 that the mere raising of urine to the temperature of 212° Fahr. is not sufficient 

 to ensure the destruction of the vitality of the tough-lived germs which it may 

 contain ; but that it is essential for that purpose to maintain the liquid for some 

 minutes at the boiling-point.^ But, if this be so, the germs introduced on the 

 withdrawal of the lamp, being under the same circumstances as those in urine 

 simply raised to 212° Fahr., and at once allowed to cool, should retain their 

 vitality and give rise to organic development. The explanation which has 

 occurred to myself is as follows. Immediately that the steam ceases to issue 

 from the tube on the removal of the lamp, moisture is deposited upon its 

 interior from the condensation of the aqueous vapour in it ; and this moisture 

 remains clinging to the interior of the tube, and tending to form drops at its 

 angles, however rapidly the air be driven through it. And it seems to me 

 natural that this water in the tube should arrest the particles in the air trans- 

 mitted through it. Conversely, I am inclined to think that the germs of the 

 two growths visible to the naked eye in the flask with straight and short neck 

 entered with the first rush of air, but retained their vitahty in the hot liquid, 

 as in Pasteur's experiments with urine heated to 212° Fahr., and at once cooled. 

 These two fungi had already grown to a sufficient size to be distinguishable by 

 the naked eye, within a few days of the commencement of the experiment, but 

 no other points of growth appeared during the ensuing month ; implying that 

 the germs of such fungi, though admitted at first, when the air entered rapidly, 

 were excluded by the narrow though straight neck during the slow movements 

 caused by the gradual diurnal changes of temperature. 



^ Comptes Rendus, vol. 1, p. 306, 



