EXPERIMENTAL PHYSIOLOGY. 
133 
amongst the animals which have received it, some die slowly, 
with a slight local infiltration, while others, in at least equal 
numbers, resist and survive. The liquid heated three hours 
does not kill adult animals, nor even produce sensible local ac¬ 
cident ; a fortiori —it is the same with the fluids heated during 
four hours, and even more. And the virulent agents contained 
in these harmless liquids have preserved their prolific faculty ; 
an important point to be hereafter considered. 
From the experiments that I have made, the primitive 
viruleney is in inverse, and its attenuation in direct ratio of the 
number of rudimentary spores which alter the homogenity of the 
protoplasm of the threads and of the batonnets. 
It is, then, shown that heating is an excellent means of, so to 
speak, attenuating instantaneously virulent cultures prepared in 
certain conditions. If this attenuation could be considered as 
the indice of a specific transformation, one could not hesitate to 
place heat amongst the most important agents to give to the 
protoplasm in way of evolution derivation of transformation. 
—Revue Scientifique. 
ON THE PROLIFIC FACULTY OF VIRULENT AGENTS ATTENUATED 
BY HEAT, AND THE TRANSMISSION THROUGH GENERATION 
OF THE ATTENUATING INFLUENCE OF A FIRST HEATING. 
By M. A. CiiAuvEAtr. 
One can assure himself in two ways that the attenuation by 
heat does not imply any alteration of the vitality, or of the 
prolific faculty, of virulent agents which have been deprived of 
their infectious properties by such action : 1st—Through means 
of the culture of the first generation itself, submitted to heat, in 
showing that the growth has only been temporarily suspended by 
that operation. 2d—Through the cultivation of the second gen¬ 
eration, in showing that the seminal element furnished by the 
liquid of the primitive culture, before the return of its develop¬ 
ment, fecundates perfectly a new ground. 
To utilize the first process, it is sufficient to place the matrasses 
