Only fragmentary provings. Bears the same relation to smallpox that Antitoxin does to diphtheria. An extended clinical record by competent and reliable observers attest its curative value in variola - simple, confluent and malignant - as well as in varioloid and varicella. It has done splendid work in all potencies, from the 6th cent. to the c. m. As a preventive of, or protection against, smallpox, it is far superior to crude vaccination and absolutely safe from the sequenae, especially septic and tubercular infection. The efficacy of the potency is the stumbling block to the materialist. But is it more difficult to comprehend than the infectious nature of variola, measles or pertusis? Those who have not used, like those who have not experimentally tested the law of similars, are not competent witnesses. Put it to the test and publish the failures to the world.