15^ Notes, ii. 2 — 3. 



of refrigeration, just as a small fire is more easily extinguished than a large one. In 

 other words disease, which consists in an abnormal increase or decrease of the bodily 

 heat and moisture, is the more dangerous the older the body is. Should no disease 

 intervene, the bodily heat and moisture grow less and less by gradual exhalation, until 

 at last they are expended ; but so gradual is the process that the departure of the soul 

 occurs imperceptibly and without pain, 



11. Z). G. et C. ii. 2 and 3 ; cf. ii. I, Note 3. 



12. It is a matter of familiar observation that degrees of heat 'and cold which affect 

 some persons agreeably are distressing to others ; and in disease one sometimes finds 

 a striking contrast in this respect even between different parts of the same person. 

 Thus I once had a patient who presented the following curious phenomenon. A 

 moderately hot substance applied to his right foot caused an agreeable sensj,tion of 

 warmth ; but the application of the same to the left foot made him yell, ^nd he said 

 that the sensation he experienced was not of heat but of simple pain. 



13. Olive oil can scarcely be meant, as Frantzius supposes ; for it coagulates some 

 seven degrees above the freezing-point of water. "EAojoj' is often used generally for any 

 oil,.as {H. A. vii. 3, 2) for oil of cedar. Possibly A. is here sJDeaking of fish-oil, with 

 which he was (ZT. A. iii. 17, 3) well acquainted, and which remains fluid at a temperature 

 considerably below the. freezing-point of water. 



14. Because in A.'s opinion it derives its heat from the heart, or from the celestial heat 

 which has its main seat in the heart. 



15. The more obvious phenomena of heat and cold can.be explained equally well 

 either by supposing both of these to be actual existences with opposite characters, or 

 by supposing one of them to be merely the absence or privation of the other. Which 

 of these two views was the right one was the subject of early and often-renewed dispute. 

 Plutarch {fie primo frigido) discusses the question and answers it in the same sense as 

 Aristotle. In stating however the opposite opinion Plutarch incidentally touches on 

 what would I fancy be given by modem physicists as the reason for holding cold to 

 be no more than privation of heat. "Is there," he asks, in beginning his treatise, 

 •'such a thing actually existing as cold ? or is cold nothing more than privation of heat, 

 as darkness is privation of light and immobility privation of motion ? For in fact cold 

 appears to be quiescent, and heat to be a source of motion " (^Tret koI rb xpvxpov ^oiKe ardtriixoy 

 flfai, Kivi\riKov 5e rh Oepfiov). 



16. "Limus ut hie durescit, et hsec ut cera liquescit, * 



Uno eodemque igne." — Virgil. 



17. Cf. ii. 4, Note 10. 



18. Had A. possessed the thermometer or similar instrument he would have seen that 

 in some of his instances the difference is only one of degree. That boiling water for 

 instance acts differently from red-hot iron, because its temperature is enormously inferior. 

 It is worth noticing how well A. has here escaped the popular error, according to which, 

 in all bodies which are ordinarily designated by a common adjective, there must be one 

 common elementary property corresponding to this common title. From this tyranny 

 of an adjective, as Whewell calls it, even Bacon was not free. Among his "instantiae 

 convenientes in naturam calidi " we find nasturtium which is hot to the tongue, acids 

 which hotly burn the skin, fur and other hot coverings, spirits of wine which, as hot 

 bodies, coagulate white of egg, and so on ; the mere verbal link serving to bind together 

 most diverse phenomena. 



(Ch. 3.) 1. The external influence is the heat of the heart, to which A. attributes 

 that of the blood (cf. ii. 2, Note 14). 



