"alembic" and "serpentina" answering to the "still" and "worm" of the modern distiller. Harvey, therefore, utilizes the Galenic analogy between concoction in the lungs and that of the blood and the vapors thereof, rejecting not only Galen's preliminary concoction of air into spirits in the lungs, but also Columbus's union in the lungs of blood with spirits produced in the lungs themselves out of air. Of the entrance of "the substance of air" into the blood Harvey makes emphatic denial and, by so doing, reduces the spirits either to emanations from ingredients of the body itself (thus reminding us of Aristotle), or to a mere name with which to label qualities of the blood, in treating of which he often uses the word "spirits" as a current term. Naturally, therefore, where in his lecture notes he treats of the spirits in relation to the brain and nerves his conclusions are not clearly defined, but seem consistent with his views as to the spirits in the blood, though his jotted words are not very easy to understand. On this subject he refers by name to Galen, three alternatives discussed by whom appear to be reviewed by Harvey, viz.: that sensation and motion result either from a progression from elsewhere of spirits in substance along and within the nerves; or from a vibration of spirits in substance which have their native seat within the nerves; or, lastly, from no movement of a substance, but from a transfer of "faculty" along the nerves by means of progressive qualitative alteration thereof, "such as is produced in air by the brightness of the sun."[76] Of these three alternatives, the last seems to commend itself most to Harvey, as we should expect; the second, next; and the first, not at all;--that is, if one may so interpret the following brief passage of his lecture notes:-- "I believe that in the nerves there is no progression of spirits, but irradiation; and that the actions from which sensation and motion result are brought about as light is in air, perhaps as the flux and reflux of the sea."[77] Also we find Harvey long years afterward saying to Riolanus:-- "Moreover, the spirits, animal, natural, vital, which dwell, contained within blind windings, in solid parts, to wit, in ligaments and nerves (especially if there be so many kinds),--these spirits are not to be regarded as so many diverse aëreal forms, nor as so many kinds of vapors."[78] In Harvey's lecture notes the subject of respiration is brought to an end with an abrupt interrogation, which seems to reveal a sudden return of doubt as to whether too much may not have been conceded in admitting a pulmonary concoction of any sort. We read:-- "N.B. If the blood receive concoction in the lungs, why does it not traverse the lungs in the embryo?"[79]