Had William Harvey possessed this idea in his earlier years, and pursued it as he did that of the blood never moving in the veins but in one recurrent course, he would at least have prepared the way for another grand discovery in physiology: demonstrating the erroneousness of the current physiological notions on the use of the lungs, he would have led the van in the investigation of their proper office; and, had everything else permitted, he might even have anticipated Joseph Black in explaining the source of animal heat. But this was an impossibility at the time: chemistry, in Harvey’s day, mostly in the hands of adepts and charlatans, transmuters of the base metals, and searchers after the philosopher’s stone and the elixir of life, could have no attractions for the clear intellect of the demonstrator of the circulation of the blood. No wonder, therefore, that Harvey “did not care for chymistrey,” or that “he was wont to speak against the chymists” (Aubrey, l. c. p. 385); this anecdote is but another proof of Harvey’s sagacity. Harvey then could only show himself in advance of his age by questioning its opinions on the office of the lungs as he does; the state of chemical science in the middle of the 17th century did not admit of his doing more. Harvey, however, well knew the vivifying force of heat: he saw it the immediate indispensable agent in the reproduction of a living sentient being, as it is probably employed by the Creator as mainspring in the elaborate mechanism of the automatic animal body. * * * * * The short piece on the ANATOMY of THOMAS PARR, is interesting in itself; and in giving us a glimpse of Harvey’s style of pathological reasoning, confirms us in our faith in the great physiologist as a practitioner of medicine. If knowledge will not help, how should the want of it avail? * * * * * The LETTERS of Great men generally serve to make us more intimately acquainted with them than without such aid we could have become. This is more especially the case as respects the letters that are written in the ease and confidence of private friendship. It is greatly to be regretted that so few of the letters of this description that flowed from the pen of Harvey should have come down to us. Those addressed to Giovanni Nardi, however, show us what an affectionate and elegant mind our Harvey possessed; how mindful he always appears of former kindnesses to himself and to those that were near to him; how anxious that he should be cherished in the memory of his friends, even as he cherishes them in his own!