Mr. Thomas Brown, a surgeon of Musselburgh, published in 1809 a volume giving his experiences of the results of vaccination. He had at first accepted and practised it. He also applied the “variolous test” with apparent success, and thereafter went on vaccinating in full confidence that it was protective against small-pox, till 1808, when, during an epidemic, many of his patients caught the disease from two to eight years after vaccination. He gives the details of forty-eight cases, all within his own personal knowledge, and he says he knew of many others. He then again tried the “variolous test,” and found twelve cases in which it entirely failed, the result being exactly as with those who were inoculated without previous vaccination. These cases, with extracts from Brown’s work, were brought before the Royal Commission by Professor Crookshank. (See 4th Report, Q. 11,852.) Again, Mr. William Tebb brought before the Commission a paper by Dr. Maclean, in the _Medical Observer_ of 1810, giving =535= cases of small-pox after vaccination, of which =97= were fatal. He also gave =150= cases of diseases from cow-pox, with the names of ten medical men, including two Professors of Anatomy, who had suffered in their own families from vaccination. The following striking passage is quoted:—“_Doctrine._—Vaccination or Cow-pox inoculation is a perfect preventive of small-pox during life. (Jenner, etc.) _Refutation._—535 cases of small-pox after cow-pox. _Doctrine._—Cow-pox renders small-pox milder. It is never fatal. _Refutation._—97 deaths from small-pox after cow-pox and from cow-pox diseases.”