7thly, Much is to be attributed to the nitrous fumigation. In several instances it was attended with the best effects. The lamps, with this, were kept constantly burning in the observation-rooms, and in the rooms from which the cases of the plague had come. Vessels, with the materials for the fumigation, were likewise placed under the beds, and in the corners of the rooms. When our stock of nitric was at length exhausted, we substituted marine salt for it; but this fumigation could not be kept up in rooms were the patients were all confined to their beds.
OF THE OPHTHALMIA OF EGYPT.
The other endemic, and next to the plague in importance, is the ophthalmia of Egypt; which, though a less fatal, is a more distressing, malady.
In Egypt, at particular seasons, it is a most generally-prevailing disease. It is not confined to the human race; the animals of the country, particularly the dogs and camels, are subject to its attacks. Travellers (and, if I remember, Volney is one) describe the same disease as prevailing in Syria; and, I am informed, by my friend Dr Short, that, in Persia, ophthalmia is a most frequent and severe disease.
In Egypt this disease proved most distressing and obstinate. The French, it was said, sent from Egypt to France 1000 blind men.
The number sent home from the English army was very considerable likewise. Of the Indian army, 50 were sent home invalids from blindness; most of whom were from the 10th and 88th regiments.
Ophthalmia prevailed most in the 61st regiment; after them, in the 86th regiment: while the 8th dragoons, the artillery, and the 80th regiment, had very little of the disease.
It was remarked, at all times, that the disease was seen much less frequently, and with less violence, in the native Indian, than in the European, corps. Of the former, the 1st Bombay regiment had much more ophthalmia than any other corps of natives. It was said, that, in the English army, the disease prevailed most in the dragoon-regiments. The 26th dragoons was mentioned as a particular instance of this: that corps alone, I heard, sent home about 40 invalids from ophthalmia.
Several gentlemen thought that this disease, in Egypt, was contagious.[6] So singular an opinion I would hesitate to offer on slender grounds. However, the remarkable prevalence of the disease in particular regiments, and even in particular companies of regiments, while the same general causes prevailed every where, will not be easily accounted for, without admitting something of the kind. In some corps of the army from England, as well as that from India, this was observed. In the 54th regiment, my friend, Mr Ross, then the surgeon of it, informed me that the disease was for some time not only confined to particular companies, but to particular tents. It deserves mention, too, that, till the arrival of the Indian army at Ghiza, ophthalmia did not appear in the army. We found at Ghiza the 89th regiment and an ophthalmia-hospital of the English army.
I believe that several diseases are contagious, which are not suspected to arise from such a cause: the theory of contagion is but very imperfectly understood.