Though I have principally written with an intent to be understood by masters of ships who carry no surgeon; yet I am well persuaded that every practitioner, whether on sea or shore, will find many things to his improvement. With respect to my receipts, they are simple and powerful; yet I do not enjoin so strict a conformity to them, by the practitioner, who has an extensive knowledge of the _materia medica_, and is prepossessed in favour of some particular medicines; but as he will discover my indications, it may serve greatly to compare that of mine with his own, and then he may judge for himself. I have touched very slightly on the requisite diet for patients on board a ship; though this is an essential article regarding health in general: But I found that subject also of so very extensive a kind, that it would swell the book; but as I have many valuable things to offer of the same nature, I must beg, that in the mean time, the reader will be satisfied with the universal observations in general; namely, that temperance is the principal object and that patients who are deprived of exercise ought to have the most easy digesting food. Copper and lead are pernicious; but iron and earthen ware are safest either on sea or shore. In order to render the book as useful as my zeal has intended, I recommend it a fair perusal, from the first page to the last; a book of this nature is apt to be looked into, only when advice is wanted: that method is wrong; and in such a case, the best book in the world is apt to mislead. It is not enough that we know what we are to do with such and such disorders, but we should previously know what the disorder is; and how shall we know that, without having some idea of the evil before it comes on? A book of this size is soon perused; taking a lecture or a section at a leisure time on board, will soon send the reader through the whole; and I flatter myself, that one perusal will lead to the second, when then it may be referred to for advice with safety; and I hope a study so essential to self-preservation, will be viewed in a more agreeable light, than it has hitherto been. To compleat the whole, a copper-plate is annexed, wherein the most material utensils are exhibited, which was scarce capable to be explained by bare description, to men unacquainted with surgery. To conclude, I must beg leave to observe, that the respect and esteem, with which I have been constantly honoured by every worthy seaman, whose life and health were committed to my care, have I confess, stimulated my endeavours, to offer them this book as a grateful return. And I am happy to reflect, that my experience in life enables me to make it worth their acceptance. May they reap that benefit from it, which my heart has intended them; and this is all the reward I wish to obtain. N. D. FALCK. ------------------------------------------------------------------------