186 



Dr. F. Crace-Calvert on Putrefaction. [Feb. 29, 



closed for twenty-seven days, during which it was observed that the albu- 

 men in the bulb containing oxygen speedily became turbid, then the one 

 containing air, while the other three remained clear. After this period the 

 tubes were broken and the contents examined. A large quantity of vibrio- 

 life was found in those containing oxygen and common air, whilst those 

 containing nitrogen, carbonic acid, and hydrogen contained very small 

 quantities, that with hydrogen the least, — thus provi ng that oxygen is an 

 essential element to the production of putrefactive vibrios. 



In further support of this view, I may state that under certain conditions 

 these animalcules produce such an amount of carbonic acid and other gases 

 as to exclude oxygen to such an extent that their own development and life 

 are impaired. 



This is easily proved by taking albumen full of animalcules, but not 

 emitting any putrid odour, and placing it in test-tubes, closing some and 

 leaving others open. If these tubes are examined after a few weeks, it 

 will be observed that in those left in the air life has much increased, and 

 they emit a very putrid odour ; whilst the life in the closed tubes not only has 

 not increased, but appears to be in a dormant condition ; for if the corks 

 are removed and the fluid again comes in contact with the oxygen of the 

 air, its activity returns. The albumen also in the closed tubes does not 

 emit any putrid odour. 



M. Pasteur has also found that oxygen was necessary to the vibrios of 

 putrefaction, although the same gas destroyed those produced in butyric 

 fermentation ; but he has not made any experiments to show that the pro- 

 ducts emitted by such vibrios are prejudicial to their development, and 

 even to their power of locomotion. 



Having stated above that liquids exposed to the atmosphere become im- 

 pregnated with monads, I will now try to describe their gradual develop- 

 ment into vibrios, and their ultimate transformation into microzyma. 



A few hours after the albuminous fluid becomes impregnated, the monads, 

 which have a diameter of about T28 1 00 of an inch, appear to form 

 masses. Then some of the monads become elongated into vibrios, which, 

 though attached to the mass, have an independent motion ; so that as the 

 force exerted by the vibrios predominates towards one or another direc- 

 tion, so is the mass moved over the field of the microscope. As the deve- 

 lopment proceeds, the mass is broken up, and ultimately each vibrio has 

 an independent existence, and may be seen swimming or rolling about in 

 the fluid. Their size at this stage is about ^ owo" °f an mc h. These, 

 which I call ordinary vibrios, gradually grow into long vibrios, which attain 

 a length of -g^Vo" °f an i nc b. 



These long vibrios gradually become changed into cells, which I have 

 called microzyms. The first process in the transformation is its division 

 into two independent bodies. One extremely faint line appears across the 

 centre of the animalcule, and increases in distinctness until the vibrio ap- 

 pears like two smaller vibrios joined together. The separation takes place 



