According to Luke 22:44, our Lord's sweat was 'as great drops of blood falling to the ground.' Michaelis takes the passage to mean nothing more than that the drops were as large as falling drops of blood. This, which also appears to be a common explanation, is liable to some objection. For, if an ordinary observer compares a fluid which he is accustomed to see colorless, to blood, which is so well known and so well characterized by its color, and does not specify any particular point of resemblance, he would more naturally be understood to allude to the color, since it is the most prominent and characteristic quality.
There are several cases recorded by the older medical writers, under the title of bloody sweat. With the exception of one or two instances, not above suspicion of fraud, they have, however, all been cases of general hemorrhagic disease, in which blood has flowed from different parts of the body, such as the nose, eyes, ears, lungs, stomach, and bowels, and, lastly, from various parts of the skin. When blood oozes from the skin, it must reach the external surface through orifices in the epidermis, which have been produced by rupture, or we must suppose that it has been extravasated into the sweat-ducts. But, even in this latter case, we must no more consider hemorrhage of the skin to be a modification of the function of sweating, than bleeding from the nose to be a modification of the secretion of mucus. The blood is simply mixed with the sweat, precisely in the same way as, when spit up from the lungs, it is mixed with mucus and saliva in passing through the air-tubes and mouth. It is, therefore, incorrect to suppose that hemorrhage from the skin indicates a state of body at all analogous to that which occasions sweating.
But while experience teaches that cutaneous hemorrhage, when it does occur, is the result of disease, or, at any rate, of a very peculiar idiosyncrasy, and is in no way indicative of the state of the mind, daily experience and the accumulated testimony of ages prove that intense mental emotion and pain produce on the body effects even severer in degree, but of a very different nature. It is familiar to all that terror will blanch the hair, occasion momentary paralysis, fainting, convulsions, melancholy, imbecility, and even sudden death. Excessive grief and joy will produce some of the worst of these. Sweat is caused by fear, and by bodily pain; but not by sorrow, which excites no secretion except tears.
It is very evident, then, that medical experience does not bear at all upon the words of St. Luke. The circumstances connected with our Lord's sufferings in the garden must be considered by themselves, without any reference to actual observation; otherwise, we shall be in danger of rendering a statement, which may be easily received on its own grounds, obscure and contradictory.