124 



NATURE 



\_ynnc ic, i8So 



heat, it is further established by experiment that in this 

 case the energy of motion does really persist as such. 

 Thus a gas consists of molecules flying about with great 

 velocity, rotating and vibrating, and so having energy of 

 motion. All this energy of motion is what we call heat, 

 and thus heat is a repetition of a known meaning of 

 energy. Again, heat exists between a radiating body 

 and the thing it warms ; now the intermediate space 

 is filled by the luminiferous ether, which, being elastic, 

 has in its ultimate parts both energy of motion and 

 energy of position. In these forms the heat exists in the 

 space in question. 



In the cases of heat and electricity the foi-m of the persist- 

 ing energy is pretty well ascertained. But there are cases in 

 which we do not know if it is energy of motion or energy of 

 position, such as that of cJuinical cncrgv. In the burning 

 of coal there is a falling together of carbon and oxygen 

 [and heat is produced] ; but we do not know in which of 

 the two forms, if either, the energy which comes out as 

 heat existed in the chemical process. For such a case the 

 conservation of energy is only a probable statement 

 (though of great probability) to the effect that in all cases 

 where a physical quality is convertible with energy, that 

 quality is itself either energy of motion or energy of 

 position. 



General Results. — Force is a quality of position, definite 

 in magnitude and direction at any point ; not constant. 



Energy is the name of two different quantities. 



1. Energy of motion, half the rate at which a body 

 carries momentum. 



2. Energy of position, defined by the statement of the 

 law that the work done in getting from one position to 

 another is the same by whatever path the change of 

 position is made. 



[The definition of these conceptions helps to clear up 

 sundry questions of mixed physics and metaphysics.] 



1. Is a physical force, such as the attraction of the 

 earth, analogous to our "exertion of force" in muscular 

 work ? No, for the sensation of muscular effort is very 

 complicated. It involves nerve and muscle, which we 

 know not to be present in the simpler cases, e.g., the 

 motion of a stone let fall. To talk of pusjdng or pulling 

 in such a case is a personification of external nature. 



2. Are we directly conscious of force ? It is often said 

 in physical and metaphysical works that we are. It may 

 be true, but it is at least premature. We do not know 

 that the chemical changes in nerve-matter corresponding 

 to consciousness are energy [only that they are conveiiible 

 luith dynamical energy] ; much less do we know that they 

 are force. If they are energy, it is energy of motion, not 

 energy of position, since consciousness does not depend on 

 the position of the nerve-matter [so my notes : scdqua:)e\ 



3. Is mind a force .' It is held by some that the will 

 acts as the match to gunpowder, by setting loose a store 

 of energy, the matter of the brain being in unstable equi- 

 librium. But you cannot have in nature an absolutely 

 unstable equilibrium [/.f., an equilibrium capable of being 

 upset by an infinitesimal force], because the universe is not 

 at rest [and every motion in the universe produces a finite 

 change, however small, in the resultant force at every 

 point of space]. Therefore if mind is force, operating 

 in the way suggested, it must be able to create a deter- 

 minate quantity of energy. This is a supposition which, 

 if true, would destroy its own evidence ; for it would 

 destroy the uniformity of nature, on which all possibility 

 of inference ultimately rests. 



[The discourse concluded by pointing out that even 

 from a purely scientific point of vie\v, metaphysical 

 speculation is to be encouraged as a spur to science.] 



EC HIS CARINATA 

 'X'HOSE who are interested in the poisonous snakes 

 ■*■ of India may have an opportunity of seeing one 

 of the most interesting and destructive of these reptiles. 



now in the Zoological Society's Gardens in Regent's 

 Park. 



The snake I refer to is a fine specimen of the Echis 

 carhiata, which has recently arrived from India, and is 

 the first of its kind, I am told, that has been received 

 alive in this collection. I think it is probable, however, 

 that a snake so common in some parts of India must have 

 been brought alive to England before ; but at any rate it 

 is rare, and sufficiently interesting to claim attention, 

 especially as it is healthy, vigorous, and active, and readily 

 shows its peculiar habits, in the attitude it assumes and 

 the rustling sound it gives rise to by the friction of the 

 carinated scales of one fold of its body against those of 

 the other when alarmed, and in the aggressive position 

 which it takes up when prepared to strike, which it does 

 most viciously by launching out its head and the anterior 

 part of its body from the centre of the convoluted folds 

 into which it has arranged itself. There are, I believe, 

 only two true vipers in India (though there are several 

 Crotalidre), the Daboia russellii, or chain viper, or 

 ticpolonga, and the Echis carinaia. The daboia is 

 well known here, and there are, or have been lately, 

 fine specimens in the Society's collection ; but the 

 echis is not so well known, though common enough in 

 India. 



It is much smaller than the Daboia, and is very active 

 and dangerous. It is known in Sind as the "kuppur" ; in 

 other parts of the country as " phoorsa " ; about Delhi it 

 is "afiie," or "afai" (a word of Arabic origin). Russell calls 

 it "horatta pam." It seldomattains more than the length 

 of 20 to 22 or 23 inches; probably 15 or 16 inches is 

 more common, and is from 2 to 2J or 3 inches in circum- 

 ference at the thickest part of the body. 



It is very fierce and aggressive, always ready to attack. 

 It throws itself into a double coil, the folds of which are 

 in perpetual motion ; the w'hole body does not necessarily 

 change its place, and as they rub against each other they 

 make a loud rustling sound, which may be mistaken for 

 hissing. This is produced by the three or four outer rows 

 of carinated scales, which are prominent and point down- 

 wards at a different angle to the rest ; their friction 

 against each other causes the loud rustling sound which 

 gives notice of the presence of the echis, as does the 

 rattle of the crotalus. 



I have never heard this viper hiss ; though the daboia 

 does so loudly. It is of a brownish-grey colour, with white 

 and dark spots, and a waving whitish band on either side 

 of the body. On the head there is a peculiar mark some- 

 thing like' a cross. Its fangs are very long and mobile, 

 and its poison very active, destroying a fowl in two or 

 three minutes. In Sind, and some other parts of India 

 where it is very common, it causes considerable loss of 

 human life, though I believe it is not so destructive on the 

 whole as either the cobra or Biinganis cariilcus (Krait), 

 which are more generally distributed over the peninsula. 

 I have not seen it in Bengal, but it is common in the 

 North-West Provinces, Punjab, Sind, and Central Pro- 

 vinces, and Southern India in the Carnatic, and about 

 Madras. 



Its aggressive aspect when roused, the vicious eye, its 

 pecuUar method of folding itself, the rustling of its scales, 

 and the rapidity with which it strikes, make it, when hving, 

 an object of considerable interest. 



In the same collection there is a fine specimen of 

 another very rare colubrine venous snake, the Ophio- 

 phas,its claps, which gives an opportunity not often 

 available even in India, where the snake is found only in 

 certain localities, of studying its peculiar habits and food, 

 which consists of other snakes. It is as deadly as the 

 cobra, to which it is nearly allied ; but from its com- 

 parative rarity and the nature of its habitat it does not 

 contribute so largely to the death-rate as that snake or 

 even a'; the little echis. 



J. Favrer 



