6 



Transactions of the Socidy. 



By this we can see it (if a destructive heat should not have been used) 

 in various recognizable stages of development, and follow them to 

 the final stage, and determine relatively the thermal death-point as 

 compared with that in air. 



The instrument was devised and first used by me in recently 

 working out all the points of the " Life-history of a Minute Septic 

 Organism."* But I have also applied it gradually to the determi- 

 nation of the point of heat destructive to the germs of each of the six 

 monads whose life-histories have been detailed in the Transactions 

 of this Society, and the results, which appear to me to be of con- 

 siderable importance, I shall proceed briefly to state. 



It is necessary, however, that the nature of the apparatus used 

 should be understood. It is formed throughout of blown glass, 

 and is, in brief, a small vessel capable of receiving the putrescent 

 fluid containing a given organism, as a reservoir communicating 

 with a cell into which the fluid will flow, and in which the 

 behaviour of the organism in any stage can be microscopically 



Fig. 1. 



studied ; and the whole is so arranged that it can be heated and 

 closed hermetically and examined for an indefinite time. 



Fig. 2. 



Drawings made directly from the instruments are given in Figs. 

 1 , 2, and 3. But it is only by means of a diagram that they 

 can be fully understood. Fig. 4 is a diagram of Fig. 2. A is 



♦ ' Proc. Ruy. So-.,' xxvii. (1878) p. .332. 



