Classicly

 The eastern practice of inoculation was first made known in this country by Lady Wortley Montagu, who was the wife of our ambassador at Constantinople, where she had seen it tried with good effect. Inoculation consisted in transferring the matter of the smallpox pustule from the body of one suffering from the disease to that of one not as yet affected by the disease.

It is a fact that the form of smallpox thus communicated through the skin was less severe, and consequently less fatal, than when taken naturally, as was abundantly proved in this country. But, unfortunately, inoculated smallpox was as infectious as the natural smallpox—this fact forming the great distinction between inoculation and vaccination. The inoculated person became a centre of infection, and communicated it to many others.