312 Mr. Coleman and Prof. McKendrick [May 29, 



twenty-two days after its removal from the cold chamber. Still it 

 could not be said that this degree and duration of cold sterilised the 

 fluid. 



9. Samples of sweet ale behaved in a precisely similar manner. 



10. Samples of meat juice, made by boiling lean meat, filtering, 

 and carefully neutralising, were also operated on, both in flasks 

 hermetically sealed and having the necks stuffed with cotton-wool. 

 Exposed to temperatures of from zero to - 80^ F. for eight hours, 

 all of these in due time showed, under the microscope, numerous 

 bacteria, but the freezing process undoubtedly delayed their appear- 

 ance, and this was most marked in the samples exposed to the 

 lowest temperatures. 



11. Samples of neutralised vegetable infusion behaved in a 

 similar way. 



12. Many experiments were made with putrefying fluids, full of 

 bacteria and other micro-organisms. The method followed was to 

 examine the fluid with the microscope, and to note the appearances of 

 the organisms. Then portions of the fluid were placed either in a 

 flask plugged with cotton-wool or in a hermetically-sealed flask, and 

 exposed to the lowest temperature attainable —namely, — 120^ F. 

 In one set of experiments such organisms were exposed to — 120^ F. 

 for 100 consecutive hours. The thawed fluid was again examined 

 microscopically, with the result of showing that the organisms were 

 motionless. Still it could not be asserted that they, or at all events 

 their spores, were dead, as, after exposure to a temj)erature of 80° F. 

 for a few hours, the fluid was found to be again teeming with 

 organisms in active movement. The conclusion arrived at was that 

 such prolonged exposure to cold did not kill them all, probably 

 leaving spores unaffected. 



13. It was also attempted, by repeated freezings and thawings, to 

 kill micro-organisms, as it was conceivable that cold might kill the 

 adults only, leaving the spores unaffected. If, then, the spores were 

 killed as they approached maturity, and before they had produced 

 new spores, it might be possible to sterilise the fluid. All attempts 

 in this direction were unsuccessful. 



14. Experiments were also made with gelatinous infusions of meat, 

 to which grape sugar had been added. Exposure to low tempera- 

 tures and thawing did not destroy the gelatinous character of the 

 substance, but putrefaction was not prevented. Such gelatinous 

 masses, after exposure for 100 consecutive hours to — 120^ F., 

 and subsequently for fifteen to twenty hours in a warm room of 80° 

 F., became filled with bubbles of imprisoned gas, each bubble being 

 the outcome of one or more organisms. 



15. It is a striking consideration that freezing at low tempera- 

 tures makes a mass of organic matter solid throughout, so that it 

 can only be broken to pieces by violent blows of a hammer. Beef 

 has then a fractured surface like a piece of rock. Mutton is friable. 



