How the clamorous opposition to Horsegrease had deprived Hindoos of the earlier blessing of vaccination, we are left to conjecture. Perhaps he meant that Horsegrease would have borne transit to India better than Cowpox, or that the Hindoos themselves might have resorted to horses with greasy heels. In reply, 22nd April, 1803, De Carro wrote to Jenner commending his moderation in maintaining silence toward his antagonists--little apprehending the motives of that silence. Pearson’s conduct, he thought, bordered on insanity. “I am extremely glad,” he continued, “that you have treated it with the contempt it deserves, though I am happy to see that your friends have exposed his ridiculous and malevolent designs.” De Carro was intimate with Sacco of Milan, and from him received virus derived from Horsegrease, which he used indiscriminately with Cowpox, until in Vienna it was unknown who were vaccinated and who equinated.[147] De Carro was also in correspondence with Dr. La Font, a French physician, established at Salonica, who was likewise a Horsegreaser. He discovered that the Macedonian farriers recognised three sorts of grease in horses, called in general _javart_, and discriminated as _l’écrouelleux, le phlegmoneux, et la variolique_.[148] With the variolous grease, La Font inoculated two boys, and from them other children, reproducing the experience of Loy of Whitby and Sacco of Milan. De Carro in communicating La Font’s success to Jenner, 21st June, 1803, observed, “These particulars, I hope, will silence all those who still doubt the truth of your doctrine as to the connection of Grease, Cowpox, and Smallpox”--Jenner holding that Smallpox was a malignant variety of Cowpox, whilst Cowpox came out of Horsegrease.