Thus have I laid before you the chief causes, from which the diseases incident to the studious take rise; and I should never make an end, were I to enumerate the inferior causes, which professors have a bad custom of assigning from their own invention: I shall therefore pass by all the secondary causes. But there are men, truly learned, illustrious votaries of the muses, who, besides the disorders that spring from too assiduous an application of mind, experience others, owing to the nature of the object that engages them. Anatomists often contract malignant fevers by breathing putrid air, and other diseases from the corruption of the bile, from the matter in which their hands are constantly immersed, a slight excoriation arising, or an inconsiderable wound, which sometimes end in their deaths. Chemical experiments are attended with danger, and an acid smoke, of a very penetrating nature, would have kill’d the great BOERHAAVE, if there had not been at hand an alcaline spirit, which overcame the acid and expanded the compressed lungs. Botanists have been often hurt by the plants for which they have so strong a passion. These, and the like, rather relate to the disorders of artificers, (excuse the expression); but this discourse turns upon the disorders which study brings upon some of the organs. The first that offer are the eyes, which constant attention so fatigues, that I have often seen doctors who had not attain’d to their thirtieth year, and yet could hardly bear the light, especially candle-light; and were scarce able to read a few pages without their eyes being suffused with tears, then growing dim, and at last quite incapable to distinguish any object. But the eyes are much sooner and much more easily affected by reading at night; for there is not a man living who has not experienc’d, at least once in his life, how much they suffer by the motion of light and the irritation of smoke.