Are other diseases ever produced by vaccination?--The popular belief would answer this question in the affirmative. All affections of the skin and swelling's of the glands noticed in children soon after vaccination, are attributed by parents in many cases to this operation. They forget that such diseases are met with constantly in infancy and childhood, as often among the unvaccinated as the vaccinated. Observation does not show that they occur with greater frequency among the vaccinated. An English physician has been at the trouble to examine and record a thousand cases of skin disease in children: he found no evidence whatever that vaccination disposes the constitution to such affections. It has been stated with apparent justness, that parental complaints of this kind frequently arise from their unwillingness to believe there is anything wrong in their offspring. Hence, when other diseases follow, vaccination gets blamed for what is really and truly due to other causes. So far from doing any harm to the system, it has been observed in those countries where vaccination has been most thoroughly practised, that, leaving small-pox out of the question, there have been fewer deaths from other maladies. This is especially true of two of the most important classes of diseases, namely, scrofulous affections and low fever. For this reason, some medical statisticians have attributed to vaccination an indirect protective influence against these disorders. At what _age_ should the child be vaccinated?--If the health permit, the operation should always be performed in very early infancy. The chief sufferers from small-pox are young children. One-fourth of all who die from this fatal disease in England are children under the age of one year. In Scotland, where until recently vaccination has been much more neglected than in England, the proportion even amounted to nearly one-third; and of these, one-fourth were under the age of three months. The great risk, particularly in large towns, where small-pox is seldom absent, of delaying vaccination is obvious. City children, if hearty, should be vaccinated when a month or six weeks old. Rarely or never ought it to be delayed beyond two or three months. This early period of life is also particularly suitable to vaccination, because the accompanying fever will then be over before the disturbing influence of teething begins. RE-VACCINATION.