This cowpox is commended as “pure lymph from the calf,” a sweet periphrase with a savour of Daphne and Chloe, of Flora and the country green--a periphrase used in craft or ignorance, “pure lymph” being as incapable of producing vaccinia as pure milk or pure saliva. The prescription takes us back to Jenner’s time and Jenner’s procedure. As has been said, the Gloucestershire dairymaids believed that after cowpox they were safe from smallpox, and that Jenner was much impressed with their belief until he discovered that it was untrue. Had he found it true, he might have advertised the prophylactic thirty years in advance of the publication of his _Inquiry_; but if anything was certain, this was certain, that cowpox did not avert smallpox. Satisfied that cowpox _per se_ was of no avail against smallpox, he defined a variety of cowpox generated by the application of horsegrease, to which he was pleased to ascribe sovereign efficacy. Why, I ask, did he discriminate and prescribe that variety of cowpox if cowpox _per se_ was effective? The question answers itself. I will not say the cowpoxers treat Jenner’s evidence with disrespect; for such is their ignorance, that I question if they are aware of its existence; moreover, that which is undesirable to know, is instinctively avoided and kept out of sight. They recommend their “lymph” as wonderfully mild, being attended with no erysipelas, the pest of arm-to-arm vaccination--a description that tallies exactly with Jenner’s of impotent cowpox. “The pustules,” says Jenner, “are of a much milder nature” than those of horsegrease cowpox. “_No erysipelas attends them_, and they are incapable of producing any specific effect on the human constitution.” A COWPOX CHARLATAN. Yet, incredible as it may appear, it is with the praise of this impotent cowpox, attended with no erysipelas, that the public have been deafened, and for which the most extravagant assertions are made. Dr. Martin, one of the chief producers and vendors of the article, appeared at the British Medical Association in 1881, saying, “I am called upon at times, at the very shortest notice, to vaccinate whole cities; and when I left America, I had just completed the vaccination of the city of New Haven. The custom is to send for me, or my son, wherever smallpox breaks out, with orders to vaccinate at once the entire population of the city, town, or neighbourhood. It is done immediately, the result being that an epidemic is completely stopped in a week.” Thus spoke the charlatan, with the acquiescence of the medical assembly. When churchmen deplore the scepticism of the age, and the decay of faith, it is to be observed that the habit of mind is limited to certain modes of opinion, and that in general we are as credulous as ever. Human nature in its structure is curiously immutable. Wherein is the advantage to disbelieve in witchcraft and to believe that epidemics of smallpox can be stopped with cowpox? A DECOROUS UNANIMITY.