Nor is the case against vaccination yet complete. The virus used is not only Vaccinia, but more than Vaccinia; for it is impossible to propagate virus from child to child without taking up other qualities. This was clearly foreseen by the variolators when vaccination was introduced--_they_ making it a point to take smallpox for inoculation from _known_ and _sound_ subjects. They maintained that cowpox transferred indiscriminately from arm to arm _must_ acquire and convey constitutional taints; and their prognostication was speedily and grievously fulfilled in the item of syphilis. Notwithstanding, the fact was furiously contested. It was said that parents used vaccination as a screen for their own wickedness; and assertion alternated with denial even to our own day. At last the conflict is at an end. The evidence has grown too multitudinous and deadly for evasion. The invaccination of syphilis is admitted, and any question is reserved for the degree of frequency. Some are pleased to describe the risk as infinitesimal, but their pleasure stands for nothing but itself. Deeds are expressive beyond words. The wide resort to animal vaccination on the Continent and in the United States has but one interpretation. Doctors and patients do not abandon what is easy for what is troublesome, nor incur the risk of the communication of bovine disorders unless under the influence of over-mastering terror. STATISTICAL EVIDENCE OF EXTRA DISEASE. Relations of individual experience may be disregarded as untrustworthy, but the broad evidence of national statistics conveys authoritative lessons. Vaccination in England was made compulsory in 1853, stringently so in 1867, and systematically extended to the entire population. If therefore it were true that vaccination often communicates more than Vaccinia, and that it aggravates existent and excites latent disease, the proof must be manifest in the statistics of the Registrar-General. Thus argued Mr. C. H. Hopwood, and accordingly he moved in the House of Commons successively for three Returns, published as follows--VACCINATION, MORTALITY, No. 433, 1877; MORTALITY (GENERAL AND INFANT), No. 76, 1880; and DEATHS (ENGLAND AND WALES), No. 392, 1880. These Returns, charged with curious and authentic information, are little known, and have been treated with significant silence by the press. Obscurantism is not confined to ecclesiastics. Our valiant journalists who mock at the Index Expurgatorius, and abhor the Russian censorship, are in their little way as ready to act the same part in favour of established prejudice. If facts adverse to the public confidence in vaccination are revealed, it is considered no more than decent to keep them out of sight.