DISEA SES OF THE NER VO US S YS TEM. 1 65 



ters, and to study the series of effects that it is capable of producing. 



After having torn away from nature this secret, so long a time guarded, 

 that contagion is the function of the living element, that a certain number 

 of contagious diseases is possessed of this element, they have isolated it 

 from organisms where they had taken it, they have studied it in the midst 

 of artificials proper for its development and to all the manifestations of 

 its life; have submitted it to influences capable of moderating its energy, 

 and in short have resolved this wonderful problem of transforming it, it 

 the agent of death, into an agent of efficacious preservation which renders 

 invulnerable those attacked by the natural contagion of the animals which 

 have been submitted to the influence, mitigated by a systematic culture 

 of the living element of this contagion ; and this grand discovery of the 

 attenuation of the virus that the entire world has applauded as one of the 

 most wonderful acquisitions, the most marvellous that medical science 

 has ever made perhaps; this discovery which in the capital of Scotland 

 some months ago, and some days ago in the capital of Denmark, has 

 yielded to M. Pasteur one of the grand triumphs which were formerly 

 accorded to the conquerors in war. 



Hydrophobia from the beginning of time to these last hours has lived a 

 fatal disease, against which all attempts have ever and ignominiously 

 failed, and here to day, thanks to M. Pasteur and his collaborators that he has 

 associated in his work, it can be transformed into a disease wholly benig. 

 nant, which not only is compatible with life, but still has this happy 

 privilege of rendering invulnerable the organisms which have received 

 the germ, in that state of benignity, against those harmed by its terrible 

 virus, when they are inoculated in the natural conditions of intensity. To 

 render hydrophobia as harmless a disease as carbuncle has become, what 

 a marvellous problem is solved ! 



They knew positively that it was contagious, and that its exclusive mode 

 of transmission was inoculation, which might be accidental, like that 

 which results from a bite, the most frequent of all; it may be inoculation 

 by the deposit of the foam of a mad animal upon an absorbing mucous, or 

 wounded surface, or may be in short, experimental inoculation. 



When they inoculate the monkey in successive series, the energy of the 

 virulence follows a descending scale, of which the degrees can be meas- 

 ured by the increasing duration of the period in inoculation, and the 

 attenuated hydrophobia of the monkey is transmitted to the dog or rabbit; 

 the duration of the period of inoculation with these last animals is wit- 

 nessed by the proportionate long increase of the attenuation of the virus 

 which was inoculated to thenar. The application of these facts says M. 

 Pasteur places in our hands a method of vaccinating dogs against hydro- 

 phobia. 



