The relations between smallpox in man and cow-pox in the cow, claim a passing remark. Jenner believed that they were essentially the same disease, and that they had a common origin in the grease of the horse. Various experiments have been made to inoculate healthy cows with small-pox, and those of Mr. Ceely, of Aylesbury, in 1839 and of Mr. Badcock, of Brighton, in 1840, who induced vesicles by inoculating cows with small-pox virus, and thus obtained a supply of genuine vaccine lymph, place the identity of the diseases beyond all question. The disease really known as grease appears to have uothing to'clo with cow-pox or small-pox; but the horse occasionally suffers an affection which is precisely the same as the small-pox in man and the cow-pox in cows; and the lymph from this horse-pox has been successfully used for vaccination.
In conclusion, a brief paragraph must be devoted to the legal bearings of the question. In 1841 the vaccination act was passed, which made the practice of inoculating with small-pox virus unlawful. In 1853, another act, known as lord Lytteltou's vaccination act, was passed, with the view of rendering the practice of vaccination compulsory, but this, though useful as far as it goes, proved a very imperfect measure. The public
health act, passed in 1858, gives to the privy-couucil the power of appointing public vaccinators to give instruction in all practical points bearing ou vaccination, for granting certificates of proficiency, and for the vaccination of poor persons residing iu unions and parishes. They have, moreover, made arrangements for supplying lymph, guaran teed by the national vaccine board, to all medical practitioners who apply to "the registrar of the national vaccine establishment, privy-council office, London, s.w." The vaccination act of 1867 was passed to "consolidate and amend the statutes relating to vaccination in England." By it the parent must have the child vaccinated within three calendar months from the child's birth, and the vaccination must be repeated until suc cessful. The vaccination act of 1871 adds one or two new provisions.