82 DR. BASTIAN ON TKE 



After allowing the powder to remain thus immersed for four 

 hours, so as to imitate the stage of preparation of a hay -infusion, 

 some of the stirred-up mixture was added to a quantity of urine 

 having an acidity equivalent to eleven minims of liquor potassae 

 per ounce (about 2i per cent.) and a specific gravity of 1023. 

 The addition was made in the proportion of two minims of the 

 spore-containing liquid to each ounce of the urine, and with this 

 well-shaken mixture nine bulb-tubes were charged. After their 

 necks had been draw^n out, the fluid in each of them was boiled 

 over the flame for rather less than one minute, when the vessel 

 was hermetically sealed. An interval of one minute having been 

 allowed to elapse, each closed vessel was inverted and plunged 

 into a vessel of boiling water for twenty minutes. Subsequently 

 all were placed together in an incubator at a temperature of 122° 

 F., and with them a control experiment in which some of the 

 same urine had been boiled alone for twenty minutes in a small 

 flask plugged with cotton-wool, and to which some drops of the 

 original spore-containing mixture (not previously dried or heated) 

 were added, in the above-mentioned proportion, when the urine was 

 cool. This latter operation was effected by removing the cotton- 

 wool plug for an instant, allowing the spore-containing fluid to drop 

 into the urine, and then carefully replacing the plug, after the 

 manner so often adopted by Professor Lister*. 



The result of these experiments was as follows : — In sixteen 

 hours the fluid in the control experiment was notably turbid, 

 and a thin scum had formed on the surface at the expiration of 

 24 hours. The other nine fluids all remained quite clear, and 

 showed no signs of turbidity during the ten days that they were 

 retained in the incubator. 



It did not seem necessary to go any further for the present, and 

 neither did time permit of it. Enough had been done to show how 

 little exact experiment would give any countenance to the hy- 

 potheses and wild assumptions which have of late been so rife in 

 regard to the powers of endurance of Bacilli-spores — hypotheses 

 and assumptions which seemed to their authors necessary, in face 

 of the now-admitted fact that a hay-infusion will often ferment 

 after it has been boiled even for several hours. 



*■ Quart. Journ. of Microsc. Science, 1873, p. 384. 



