It is certain that the study of these maladies in animals would have been for us the source of precise knowledge, which, if well understood and explained, would have often led to their preventive treatment. This is what has occurred in the case of small-pox; it is what will one day occur in typhoid fever, in times of epidemic, as will be the case in a certain number of other general or local diseases.
In truth, some complaints now looked upon as inherent to the human species, were originally foreign to it; most parasitical diseases belong to this class. Thus man has not the _psora_, or itch--the disease does not properly belong to him; the parasite which engenders it is not bred in him, it is always transmitted to him by animals. It is the same with the tænia, or tape-worm, with the trichina, or fine hair-worm.
Medical science, instituted on the bases of comparative pathology, would have made the study of diseases in the brute creation, not the collateral, but the principal object of its inquiries. It would have applied itself to the cure of the lower animals; and whilst learning to cure them, it would have ensured the cure of men's diseases.
If such be the case, can any one believe that the treatment of diathetic and hereditary maladies would be, as they still are, insoluble problems; and that the physician would have the misery of seeing decimated, whilst he helplessly looks on, a large part of the population, condemned inevitably to die of consumption and cancer? Would every man smitten with hydrophobia be irrevocably condemned to death? Assuredly, it would not be so.
That the physician should have been reduced to the painful necessity of confessing his want of means, when medicine could be nothing more than an art, we admit; but now that science has grown up and come of age, society has a right to challenge him to do, what in past ages could not have been expected of him. Briefly, we think that the time is come, by blending comparative pathology with anatomy and physiology, to construct one of the bases of the tripod on which medical science will have to rest. The success which has already been achieved in this direction is a certain guarantee for those which we may hope for hereafter.