The sources of information, to which I had recourse, were the reports made to me, and an extensive correspondence with the medical gentlemen of the army; particularly those employed in the pest-establishments. Besides these, to which my situation, at the head of the medical department of the army from India, gave me access, other sources of information, regarding the plague, were open to me, as a Member of the Board of Health in Egypt.

Some may think the present a very short, and many may think it an incomplete account; but, I trust, it will not be found incorrect. I have purposely avoided doubtful speculations and hypotheses. Anxious, above all things, to adhere closely to facts, and keep these unmixed with any notions of my own, I have, in most cases, published the extracts from letters to me, without altering a word of the correspondence.

Of the numerous imperfection of these Sketches, I am abundantly sensible. The life of a medical man in the army is at no time very favourable to literary pursuits; mine has been peculiarly unfavourable; and I have had little time or opportunity, since I first entered the army, to attend to the ornaments of diction. For the last fifteen years of my life; mostly spent in the East Indies, West Indies, or at the Cape of Good Hope; sometimes at sea, sometimes on land; my time has been occupied in a laborious attention to my duty in the army.

Some necessary avocations oblige me to dismiss this tract in a more imperfect form than it might have appeared in, perhaps with more leisure. As it is, it conveyed to government, in India, all the information which they required; and I must mention, that it comes before the public very nearly in the state in which I presented it as a report in India. From materials in my possession, I could have enlarged most parts of it, and rendered the whole more complete; but, when I drew up the following account in India, it never occurred to me, that my imperfect Memoir would be the only medical account of the Egyptian expedition. I expected, on my arrival in England, to have found complete histories of the climate and diseases of Egypt, during the time that it was occupied by the English, from some of the medical staff of the British army; several of whom were known to be fully equal to the task. If any of these gentlemen should hereafter give to the world the medical history of this renowned campaign, my Memoir may stand in some stead: it gives some facts and it will supply some information to which no one but myself had access.

At the present moment, I have not leisure to enlarge or alter it; and some friends, who have seen the manuscript, press its publication at the present time.

In the execution of my duty, during a long and perilous voyage, and alter the most fatiguing marches, I sometimes laboured under difficulties; but my duty was in every instance much facilitated, and it would be unjust in me not to mention it. I acknowledge my obligations to all the medical gentlemen of the Indian army, by whom I was most cordially and well seconded in all that I undertook.

From the nature of the prevailing diseases, the campaign in Egypt was, in a particular degree, a service of danger. To their regret, the Indian army arrived too late in Egypt to share in any other dangers than those arising from the diseases of the country; and here, the medical gentlemen had the post of honour. The zeal, attention, and perseverance, displayed, particularly by those employed in the plague-establishments, deserve every praise. Nothing can so powerfully incite the exertions of medical men, in such circumstances of danger, as the consciousness of co-operating with the best and most enlightened of mankind, for the alleviation of human misery. Intrepidity is more a military than a medical virtue; but seldom I believe has there been a greater display of it than among the medical officers, in Egypt, whose duty it became to reside in the pest-houses.[1]

There are two names which I cannot pass over with general praise. At a period of universal alarm, and of real danger, when the plague was committing the greatest ravages, two gentlemen stepped forward, and generously volunteered their services in the pest-houses. It so happened, too, that, from their acquirements, these two were the best calculated, of any in the army, to succeed in this dangerous duty. Dr Buchan had acquired a perfect knowledge of the disease in the former year; and while on duty at the pest-house, at Aboukir, had got the infection there, soon after the memorable landing of Sir Ralph Abercrombie. Mr Price had made the history of the plague his particular study, and, from his acquaintance with the oriental languages, was peculiarly calculated to be master of every thing relating to it. As will be seen hereafter, in the execution of his duty at El-Hammed, he, likewise, caught the infection. To the exertions of these two gentlemen, the service owes much; their country very much. I would fain hope, that from them, who are so able to do it, we may look for something like a history of the plague in Egypt.

Dr Shapter, who was for some time in charge of the medical department of the Indian army, and who succeeded Mr Young, as head of the medical staff of the English Army, deserves our thanks for his very ready accommodation on every occasion, and compliance with every request for assistance, and for many things, of which an army which had traversed an immense desert was necessarily destitute.

Thus far I have discharged debts which I felt that I owed. I must add a few words more, in explanation.