tions. The earliest of these references occur in his "Commentaries on the Medical Art of Galen," published in 1612, but written a year earlier, for the "license" is dated 9 June 1611. Nelli in his life of Galileo cites the following passage: "At last we have among us an instrument by which with a bulb we measure the withdrawal of heat from all the external parts of the body and of the air; by which we discover, very surely, how much more or how much less, daily, we differ from the normal [temperature]." Burckhardt cites this passage at second hand, transcribes the Latin erroneously, and says the sentence does not occur in the copy of Sanctorius' work found in the public library at Basel, and furthermore he satisfied himself that the volume contains no reference to any instrument for measuring heat; both these statements are undoubtedly correct so far as concerns the copy of Sanctorius which Burckhardt consulted, but I have found the passage in the copy of same date preserved in the United States Army Medical Library, Washington. The paragraph occurs in Part III, column 229, and this third part was probably wanting in the volume at Basel.
The historians of physics seem to have over-
