My Lord,

Read Feb. 2, 1758.

THE honour you have done me, in condescending to peruse my Essay on the contagious Distemper among the horned Cattle, claims my most respectful thanks; and I am no less obliged to your Lordship for the just remark you made, “That before inoculation could be practised on the horned Cattle, it is necessary to bring proofs, that this disease is not susceptible more than once; and also assurances, that a recovery from the distemper by inoculation guards the beast from a second infection.”

An intire conviction of the analogy between this disease and the small-pox would not permit me to omit mentioning the great advantages, which must arise from inoculation; and therefore, my Lord, I recommend its use: nor do I find any reason to alter my opinion, after having carefully read over what has been published, and made the strictest inquiry I was able in several parts of Great Britain.

I shall, in the concisest manner possible, submit the following particulars to your Lordship’s consideration, and the learned Society, over which you so deservedly preside.

The Marquis de Courtivron, in two memoirs read before the Royal Academy of Sciences in the year 1748, and published by that learned body, relates the observations he, together with Monsieur Pelversier de Gombeau, formerly surgeon to the regiment de la Sarre, made on the rise, progress, and fatality, of the contagious distemper at Issurtille, a town in Burgundy; to which are added experiments they made, by application, digestion, and inoculation, towards communicating the disease; and concludes from the failure of these attempts, that the distemper can only be communicated from one beast to another. Besides, notwithstanding the Marquis observes[20] the regularity of the illness, the critical days, on the seventh and ninth, and particularly that all such as recovered had more or fewer pustules broke out in different parts of the body; yet[21] he will not allow of Rammazzini’s opinion, of the analogy between this distemper and the small-pox, nor that it is an eruptive fever; but ranks it as a plague.

But the Marquis goes still farther. He positively say,[22] “That in the preceding years, in the provinces of Bresse, Maconnois, and Bugey, some private persons had suffered by buying cattle recovered from the distemper, which had, at that time, the pustules remaining on them: which cattle had the distemper afterwards.” Nay, he adds that “even after recovering twice, a third infection has seized and killed many.”

No wonder, my Lord, that such positive assertions should stagger, and cause the practice of inoculation not to be received, till the nature of the disease be absolutely determined, and facts prove the contrary of what has been asserted.

In a matter of so great importance to every nation, it were to be wished, that the Marquis de Courtivron had produced attested observations of these second and third infections: for tho’ a nobleman of his rank, character, and great abilities, would not willingly impose upon the world; yet it may happen, that he may have received wrong informations.

As to the nature, rise, progress, and fatality, of this distemper at Issurtille, it appears to be the same disease as raged in these kingdoms. All the symptoms agree, as described by Rammazzini, Lancisi, the Marquis, and in my Essay. A distempered beast gave rise to the three infections. The illness was every-where the same in Italy, France, and Britain; and either terminated fatally on the fourth or fifth day, when a scouring prevented the salutary eruptions, or in some cases by abortion; and on the seventh or ninth favourably, when the pustules had regularly taken their course. Tho’ the Marquis did not observe, that any particular medicines were of use, he says, that in general acids were beneficial, especially poor thin wines somewhat sour; and that the distempered beasts were all fond of these acids[23].