Notwithstanding the complete success of this experiment, Jenner did not rush into print with it. Two years later, at the end of June, 1798, his "Inquiry into the Causes and Effects of the Variolae Vaccinae" was published. In the mean time Jenner had succeeded in demonstrating the protective quality against smallpox of vaccination, contracted either casually or by direct inoculation, in some twenty-three cases. Sixteen of these had occurred accidentally in the course of occupations connected with cows and horses; the rest were done under Jenner's directions. Among the persons inoculated was Jenner's own little second son, Robert Fitts Harding Jenner, an infant eleven months old. Jenner demonstrated conclusively that the cowpox protects the human constitution from the infection of smallpox. After Dr. Jenner had made his tests he prepared a pamphlet for publication. Before publishing, however, he thought it better to make a visit to London, so that he might have the opportunity to introduce the subject personally to friends, and demonstrate the truth of his assertion to them. He remained in London for nearly three months without being able to find any one who would submit to vaccination. The medical profession generally took very little interest in the subject and seemed to consider him sadly visionary. Under the circumstances it is not surprising that Jenner went back to Gloucestershire, and his country practice, rather disappointed. It happened, however, that soon after his return home, a distinguished London surgeon named Cline resolved to make a trial of the vaccine material which Jenner had left with his friends. The surgeon's purpose in using it, however, was not altogether to test its efficacy as a prophylactic against smallpox, but with the notion that the counterirritation thus obtained might be useful in a case which he had under treatment. Those {100} were the days when the seton and the issue were still in common use, and counterirritation was considered one of the most important remedial measures at the command of the surgeon.