Page:Popular Science Monthly Volume 49.djvu/803

Rh stop here. Again, he says: "In order to ascertain whether the boy was secure from the contagion of the smallpox, he was inoculated the 1st of July following with variolous matter immediately taken from a pustule. Several punctures were made in both arms, and the matter was carefully inserted, but no disease followed."

Some might have called the discovery complete at this point, but Jenner realized that one case is not every case, and that he must repeat the experiment, which he did scores of times, even going so far as to endanger human life in order to establish the truth of his discovery. For he goes on to say (page 41): "To convince myself that the variolous matter made use of was in a perfect state, I [at the same time that he inoculated a patient previously inoculated with cowpox] inoculated a patient with some of it who had never gone through the cowpox, and it produced the smallpox in the usual regular manner."

Previous to the introduction of vaccination in London the average annual death-rate per million from smallpox was (Newsholme, table, page 192):

Germany now has the most efficient laws of probably any country for making not only vaccination but repetition at stated intervals obligatory. As a result smallpox is rapidly disappearing. In 1888 the deaths from smallpox in the entire empire amounted to one hundred and ten, less than 2·5 per million, and the majority of these occurred on or near the boundaries of other countries. We can easily appreciate the usefulness of this. Still, during this work Jenner was persecuted and abused.

Jenner's experiments belong to the class of investigations which since 1850 Thiersch has made for cholera. Lister for inflammation of wounds, Pasteur for rabies, Koch and Pasteur for splenic fever, M. Freire for yellow fever, Koch later for cholera, and has now begun to make for consumption.

Thiersch's experiments on cholera, which caused the death of fourteen mice and proved that cholera is communicated by swallowing particles of cholera discharge, have been an important factor in the sanitary legislation of every civilized country.

Two of the London water companies experimented with cholera-polluted water upon 500,000 people, causing the death of 3,476 human beings in 1853-'54. This is the popular accidental