FOR GENERAL READERS. 



FRIDAY, JULY 20th, 1888. 



CONTENTS. 





PAGE 



Scientific Table Talk ... 

 Tennyson as a Naturalist 

 The Blackman Air Propeller — II 



Buds (illus.) 



General Notes 



Spectro-Telegraphy [illus.) 



... 49 



... 50 



(illus.) 51 



... 52 



... 55 

 - 57 



Natural History : 



Orchids, What are they ?-II. 

 Aquatic Caterpillars 

 Miscellaneous Notes 



(illus.) 59 

 ... 60 

 ... 60 



The Naturalist at the Sea-Side : 





II. The Marine Dredge .. 



... 60 



PAGE 



The Edison and Swan Electric Light 



Company v. Holland 

 The Vague Cry for Technical Education 



Reviews : 



The Book of Bee-keeping 



The Land of the Broads ■. 



HeDslow's Botany for Beginners ... 



A Catalogue of the Moths of 



India.— II 



Abstracts of Papers, Lectures, etc. : 



Mineralogical Society of Great Bri- 

 tain 



Royal Horticultural Society 



61 

 63 



64 

 64 

 65 



65 



66 

 66 



Sanitary Institute 



Liverpool Astronomical Society 

 Poisons and Poisoning ... <.. 

 The Growth of Children 



PAGE 

 .. 66 

 .. 66 

 .. 67 

 .. 69 



Correspondence : 



A Circle Problem — Cosmical Origin 

 of Hailstones — Fecundity of 

 Sparrows—The Coldness of July 



nth and 12th 70 



Recent Inventions 7* 



Sales and Exchanges 7 2 



Selected Books .' 72 



Meteorological Returns 7 2 



SCIENTIFIC TABLE TALK. 



By W. Mattieu Williams, F.R.A.S., F.C.S. 



In my last I said something that may have puzzled some 

 of my readers, viz., that the indestructibility of matter is 

 virtually the same as the conservation or indestructibility 

 of energy. 



The following passage by an eminent writer, who has 

 ably elucidated the subject of the conservation of energy, 

 shows plainly enough that an explanation of my apparent 

 heresy is demanded. 



Balfour Stewart says (Nature, vol. ii., p. 78) that 

 " the chemist has always taught us to regard quantity or 

 mass of matter as unchangeable, so that, amid the many 

 bewildering transformations of form and quality which 

 take place in the chemical world, we can always consult 

 our balance with a certainty that it will not play us false." 

 But now the physical philosopher steps in and tells us 

 that energy is quite as unchangeable as mass, and that 

 the conservation of both is equally complete. There is, 

 however, this difference between the two things — the 

 same particle of matter will always retain the same mass, 

 but it will not always retain the same energy." 



Here is stated a broad distinction between mass and 

 energy, although the mass is described as measured by 

 gravitation. Mass is regarded as inherent, while energy 

 is represented as something contingent, something sup- 

 plied to matter from outside — something demanding, as 

 Herbert Spencer says, an outside conservator to effect its 

 conservation. 



According to my view, the energy of matter is inherent, 

 and what we call the mass of matter is simply a measure 

 of its primary energy, i.e., its gravitation. As Stewart 

 says, the balance is always consistent, but what is a 

 balance but an instrument for measuring the mass of 

 matter in terms of its gravitating energy ? 



I regard that old scholastic word " inertia " as a most 

 wicked word — philosophically speaking — asthe source of 

 an incalculable heap of offences against true philosophy. 

 Matter is not inert ; those who believe it to be so are 

 scientific pagans, their paganism corresponds to that of 

 the ancients and other savages. These people imagined 

 an outside fetish, or spirit, or god, or demon to specially 

 animate moving masses ; there was Boreas, who set the 



winds a-going ; there were river gods that made the river 

 flow ; there was Apollo, to give the sun a daily ride in 

 his chariot ; there was Vulcan or Thor thumping out 

 earthquakes ; there was Jupiter, with his handful of 

 thunderbolts, transacting the business now made over to 

 the electric fluid ; and a multitude of other active movers 

 of inert matter. 



In continuation of the above-quoted passage, Stewart 

 says, " As a whole, energy is invariable, but is always 

 shifting about from particle to particle, and hence it is 

 more difficult to grasp the conception of an invariability 

 of energy than of an invariability of mass." 



Energy is thus presented as an active, meddling 

 spiritual entity — a demon or fairy always at work setting 

 dead or inert matter in motion, and possessing that 

 special attribute of the gods and demons and fairies, the 

 power of assuming various forms, according to the trick3 

 to be played or the work to be done. 



Why not reject, at once and completely, all these 

 superstitions, whether ancient or modern ? Why not 

 accept the unquestionable fact that matter is active— that 

 all the energies or forces of the universe, so far as we 

 know them, are simply the inherent activities or energies 

 of matter itself? How it became endowed with such 

 activity is a question I will not venture to approach. 



We become acquainted with the existence of matter 

 only by means of our senses - by its action upon our 

 senses. I see an object when the object is actively en- 

 gaged in emitting radiations towards my eyes. Other- 

 wise I see it not. I smell an object if it is actively 

 emitting odour. I taste those things which have certain 

 chemical activities. I hear the movements of those 

 bodies which actively transmit their tremblings to the 

 air. and thence to my auditory apparatus. I feel those 

 objects that resist my efforts to remove them, or that 

 exert an energy of cohesion resisting my passage through 

 them. 



If a world as big as Jupiter, and absolutely inert, were 

 now in front of me, touching my nose, I should be 

 unconscious of its existence. If absolutely inert, 

 it would have no energy of reaction wherewith 

 to resist my slightest forward movement; I should 

 pass through it or push it forward without sensible 

 effort. I could not see it unless it were actively emitting 



