Opinions on Epidemics and Epizootics. 285 



adviser, is an ultra-contagionist, but the most violent and 

 unphilosophical of the school is Professor Ganigee, whose 

 assertions are so reckless, and whose statements are so extra- 

 vagant, as to remove him from the category of calm scien- 

 tific inquirers. He makes contagion a hobby, and he rides it 

 to death. Dr. Lankester was imprudent enough, at the Social 

 Science Congress, to support the Gamgee hypothesis, and to 

 indulge in a general theory of contagious disorders ; and he put, 

 in perhaps the most scientific form such notions admit of, the 

 current belief of those who think diseases can be suppressed by 

 orders of the Privy Council, Acts of Parliament, and police. 

 The learned doctor condemns an imaginary doctrine that 

 diseases have " a spontaneous origin in dirt/ J and he thus pro- 

 ceeds to develop his own views: — "Take/' he says, "for 

 example, the small-pox. In order to propagate this disease, 

 there must be, first, the poison matter from a small-pox pus- 

 tule; secondly, a medium of conveyance — either the point of a 

 lancet, or an atmosphere to convey the poisonous germs ; and 

 thirdly, there must be a person predisposed to take it." 



Now in this brief paragraph we have a succession of posi- 

 tive assertions, some of which cannot be proved. We pass 

 over for the moment the question of whether they are true or 

 not. If true, they still exist only as conjectures, and require 

 the verification which full and careful inquiry alone can give. 

 If no case of small-pox can occur without its being excited by 

 the specific poison found in a small-pox pustule, either the 

 laws of nature must have changed, or a specific disease of 

 small-pox must have been created and sent perfect into the 

 world at some past and unknown time. We have heard of a 

 Professor who is of opinion that species of diseases were 

 created, as well as species of animals, and that all existing 

 diseases, and all existing animals, are lineal descendants, with 

 little variation from the primitive individual specimen. Dr. 

 Lankester does not tell us, in so many words, that he shares 

 this extraordinary faith ; but his dictum amounts implicitly to 

 this : that all past small-pox, all now existing, and all that is 

 to come, was, is, and will be the progeny and descendant of a 

 primitive specially-created case. 



We repeat that we do not now discuss whether this theory 

 be true or false ; but we are justified in saying that it is not 

 proved, and that those who hold it are not entitled to speak of 

 it as if it were an ascertained fact. 



It is probable or possible that the atmosphere may convey 

 the germs of small-pox, as Dr. Lankester declares ; but this 

 again is not known. In the case of vaccination or inoculation, 

 the lancet of the practitioner conveys into the blood of the 

 patient certain corpuscles or cells of morbific matter in an 



