With reference to your letters in reply, however, and in so far as the collection of milky fluid in the vessels of Aselli is concerned, I have not ascribed it to accident, and as if there were not certain assignable causes for its existence; but I have denied that it was found at all times in all animals, as the constant tenor of nutrition would seem to require. Nor is it requisite that a matter, already thin and much diluted, and which is to become fat after the ulterior concoction, should concrete in the dead animal. The instance of pus, I have adduced only incidentally and collaterally. The hinge upon which our whole discussion turns is the assumption that the fluid contained in the lacteal vessels of Aselli is chyle. This position I certainly do not think you demonstrate satisfactorily, when you say that chyle must be educed from the intestines, and that it can by no means be carried off by the arteries, veins, or nerves; and thence conclude that this function must be performed by the lacteals. I, however, can see no reason wherefore the innumerable veins which traverse the intestines at every point, and return to the heart the blood which they have received from the arteries, should not, at the same time, also suck up the chyle which penetrates the parts, and so transmit it to the heart; and this the rather, as it seems probable that some chyle passes immediately from the stomach before its contents have escaped into the intestines, (or how account for the rapid recovery of the spirits and strength in cases of fainting?) although no lacteals are distributed to the stomach.
With regard to the letter which you inform me you have addressed to Bartholin, I do not doubt of his replying to you as you desire; nor is there any occasion wherefore I should trouble you farther on that topic. I only say (keeping silence as to any other channels), that the nutritive juice might be as readily transported by the uterine arteries, and distilled into the uterus, as watery fluid is carried by the emulgent arteries to the kidneys. Nor can this juice be spoken of as preternatural; neither ought it to be compared to the vagitus uterinus, seeing that in pregnant women the fluid is always present, the vagitus an incident of very rare occurrence. What you say of the excrements of new-born infants differing from those of the child that has once tasted milk I do not admit; for except in the particular of colour, I scarcely perceive any difference between them, and conceive that the black hue may fairly be ascribed to the long stay of the fæces in the bowels.
Your proposal that I should attempt a solution of the true use of these newly-discovered ducts, is an undertaking of greater difficulty than comports with the old man far advanced in years, and occupied with other cares: nor can such a task be well entrusted to several hands, were even such assistance as you indicate at my command[60]; but it is not; Highmore does not live in our neighbourhood, and I have not seen him for a period of some seven years. So much I write at present, most learned sir, trusting it will be taken in good part as coming from yours,
Very sincerely and respectfully,
William Harvey.
London, 13th July, 1655 (old style).
LETTER VIII
To the very learned John Nardi, of Florence, a man distinguished alike for his virtues, life, and erudition
Most excellent Sir,—I lately received your most agreeable letter, from which I am equally delighted to learn that you are well, that you go on prosperously, and labour strenuously in our chosen studies. But I am not informed whether my letter in reply to yours, along with a few books forwarded at the same time, have come to hand or not. I should be happy to have news on this head at your earliest convenience, and also to be made acquainted with the progress you make in your “Noctes Geniales,” and other contemplated works. For I am used to solace my declining years, and to refresh my understanding, jaded with the trifles of every-day life, by reading the best works of this description. I have again to return you my best thanks for your friendly offices to my nephew when at Florence in former years; and on the arrival in Italy of another of my nephews (who is the bearer of this letter), I entreat you very earnestly that you will be pleased most kindly to favour him with any assistance or advice of which he may stand in need. For thus will you indeed do that which will be very gratifying to me. Farewell, most accomplished sir, and deign to cherish the memory of our friendship, as does most truly the admirer of all your virtues,
William Harvey.
London, Oct. 25th, in the year of the Christian era, 1655.