There are very few places, where I have ventured to alter the reading on my own conjecture, and these are all noted in the margin, where I have assigned my reasons, which, I hope, will convince the learned reader. My notes will shew in how many instances I have been obliged to the excellent epistles of Morgagni. This learned and ingenious author has, in my opinion, entered more into the spirit and true meaning of Celsus, than any of the preceding commentators[T]. [T] The first three of these epistles were annexed to an edition of Celsus, by Vulpius, at Padua, in the year 1722; five more were added to another by the same editor in the year 1752; in both which editions he has every where followed (only correcting typographical errors) the text of Almeloveen. Had there been so correct an edition of Celsus, as I think may be made, with proper judgment, from the editions and manuscripts extant, it would have shortened my labour. That Celsus divided his books into chapters, appears from several passages: whereas no person, as far as I can find, pretends, that the marginal contents came from the author himself. The editions differ in these; but as it is of small importance, I have not troubled the reader with any remarks on that article. Where I found those of Linden evidently wrong, I have endeavoured to supply the defect. With regard to the materia medica, the notes are drawn chiefly from Pliny and Dioscorides, whom I esteemed the best authors on that article. When I have given English names to any of the simples, I follow the most judicious moderns; though it must be remembered, that many of them cannot be determined with absolute certainty. Through most of the compositions the text is miserably corrupted; and what is worse, I do not find, that by comparing the various editions this part can be restored. I had once some thoughts of labouring this point particularly, but as it would have been expected I should support every alteration with proper reasons, and as I despaired of executing it so, as to meet with universal approbation, and after all it would have been more a matter of curiosity than of real use, I omitted that part of my design; besides, this must have considerably increased the number of my notes, which I have endeavoured should be as few as the nature of the undertaking would admit of. For these reasons I have closely adhered to the text of Linden, without even departing from it, where the nature of the whole composition will evidently demonstrate the proportions of several ingredients to be highly incongruous.