62 THE FLOATING-MATTER OF THE AIR. 



think, infallibly produce turbidity. Why, moreover, 

 should life be absent from the first member of the 

 present group of tubes ? I searched this again, and 

 found in it scanty but certain signs of life. This 

 augmented my perplexity. A third tube also showed 

 traces of life. I reverted to the second tube, where 

 life had been so copious, and found that in it the 

 organisms had become as scanty as m the others. I 

 confined myself for a time to the three tubes of the first 

 row of the six, going over them again and again ; 

 sometimes finding a Bacterium, here and there, but 

 sometimes finding nothing. The first extraordinary 

 exhibition of life it was found impossible to restore. 

 Doubtful of my skill as a microscopist, I took specimens 

 from the three tubes and sent them to Prof. Huxley, 

 with a request that he would be good enough to examine 

 them. 



On the 22nd the search was extended to tlie whole 

 of the tubes. Early in the day lively Bacteria were 

 found in one of them ; later on, not one of the six 

 yielded to my closest scrutiny any trace of life. On 

 the evening of the 22nd a note was received from Prof. 

 Huxley stating that a careful examination of the speci- 

 mens sent to him revealed no living thing. 



Pipettes had been employed to remove the infusion 

 from the test-tubes. They were short pieces of narrow 

 glass tubing, drawn out to a point, with a few inches of 

 india-rubber tubing attached to them. This was found 

 convenient for bending so as to reach the bottom of the 

 test-tubes. Suspicion fell upon this india-rubber. It 

 was washed, the washing-water was examined, but no 

 life was found. Distilled water had been used to cleanse 

 the pipettes, and on the morning of tlie 23)(1 I entered 

 the laboratory intending to examine it. Before dip- 

 ping a pipette into the water I inspected its point. 



