1813.] 



On Vaccination, 



285 



to preserve the inoculation for the small-pox as a means of utility 

 in certain situations. 



We answer, that in such a comparison we ought not to leave 

 out the dangers of a contagion, subtile and persevering like that 

 of the small-pox, compared with the virus of the cow-pox, 

 which can only be communicated immediately, because the 

 least alteration destroys its properties. We ought also to reckon 

 for something the hope at present entertained of being able to 

 destroy the small-pox altogether. Could houses for inoculation, 

 though established under the care of the police, be subjected to 

 laws so severe, and to a sequestration so exact, as to prevent 

 completely the spreading of the small-pox from them, some- 

 thing might be said in its favour; but whoever considers the 

 nature of man, and the state of society, must be convinced of 

 the impossibility of securing any such object. In our opinion, 

 even admitting vaccination and inoculation to be equally effi- 

 cacious in rempving other diseases, the balance in favour of vac- 

 cination is so strong that it is impossible to hesitate one moment 

 about preferring it. 



SIXTH QUESTION. 



How far can we depend upon the preservative efficacy of the 

 $ow-pox, compared with the same advantage resulting from the 

 small-pox, natural or inoculated P What consequences follow 

 from this, properly considered, in the one or the other virus P 



Nobody disputes the power of the cow-pox to preserve from 

 the small-pox : and this question, which at the commencement 

 was the most important of all, has now become only secondary 

 to various others that have been put, and most of which we 

 think we have already answered. At the same time, to this 

 question must be referred a variety of other particulars of consi- 

 derable interest, such, for example, as the distinction between 

 the true and false cow-pox, the eruptions that have been con- 

 founded with the small-pox, the changes introduced in the bills 

 of mortality by the introduction of the cow-pox, the hopes of 

 destroying the small-pox, or of driving it out of the civilized 

 world. 



The idea of the faculty of preserving from the small-pox, 

 divides itself into two questions. One may be thus stated : 

 Will an individual, after heing vaccinated, if he he placed in a 

 situation proper to produce the smcdl-pox, and ivhich usually 

 produces it, continue exempt from that disease P The solution 

 of this question can only be obtained by a multitude of experi- 

 ments ; and that solution will give, then, not absolute certainty, 

 but degrees of probability proportional to the number of experi* 

 ments undertaken to resolve the question. 



The other question js this : Is it impossible for a vaccinated 



