ATMOSPHERE IN RELATION TO PUTREFACTION AND INFECTION. 
29 
illustrious French philosopher be correct, is one of the last importance. But Pasteur’s 
labours, which have so long been considered models by most of us, have been subjected to 
rough handling of late. His reasoning has been criticised, and experiments counter to 
his have been adduced in such number and variety, and with such an appearance of 
circumstantial accuracy, as to render the evidence against him overwhelming to many 
minds. This, I have reason to know, has been the effect wrought, not only upon 
persons untrained in science, but also upon biologists of eminence both in this country 
and America. The state of medical opinion in England is correctly described in a 
recent Number of the ‘British Medical Journal,’ where, in answer to the question, 
“In what way is contagium generated and communicated'?” we have the reply 
that, notwithstanding “ an almost incalculable amount of patient labour, the actual 
results obtained, especially as regards the manner of generation of contagium, have 
been most disappointing. Observers are even yet at variance whether these minute 
particles, whose discovery we have just noticed, and other disease-germs, are always 
produced from like bodies previously existing, or whether they do not, under certain 
favourable conditions, spring into existence de novo.” 
With a view to the possible diminution of the uncertainty thus described, I beg 
without further preface to submit to the Royal Society, and especially to those who 
study the etiology of disease, the following description of the mode of procedure 
followed in this inquiry, and of the results to which it has led. 
§ 2. Method of Experiment. 
A chamber, or case, was constructed, with a glass front, its top, bottom, back, and 
sides being of wood. At the back is a little door which opens and closes on hinges, 
while into the sides are inserted two panes of glass, facing each other. The top is 
perforated in the middle by a hole 2 inches in diameter, closed air-tight by a sheet of 
india-rubber. This sheet is pierced in the middle by a pin, and through the pin-hole 
is passed the shank of a long pipette ending above in a small funnel. A circular tin 
collar, 2 inches in diameter and 1^- inch deep, surrounds the pipette, the space between 
both being packed with cotton-wool moistened by glycerine. Thus the pipette, in 
moving up and down, is not only firmly clasped by the india-rubber, but it also passes 
through a stuffing-box of sticky cotton-wool. The width of the aperture closed by the 
india-rubber secures the free lateral play of the lower end of the pipette. Into two 
other smaller apertures in the top of the cupboard are inserted, air-tight, the open ends 
of two narrow tubes, intended to connect the interior space with the atmosphere. The 
tubes are bent several times up and down, so as to intercept and retain the particles 
carried by such feeble currents as changes of temperature might cause to set in between 
the outer and the inner air. 
The bottom of the box is pierced with two rows of holes, six in a row, in which 
are fixed, air-tight, twelve test-tubes, intended to contain the liquid to be exposed to the 
action of the moteless air. 
