543 



SCIENTIFIC SIDE-LIGHTS 



Power 



I vaguely discerned the audience and ap- 

 paratus, and by the help of these external 

 appearances immediately concluded that I 

 had received the battery discharge. The in- 

 tellectual consciousness of my position was 

 restored with exceeding rapidity, but not so 

 the optical consciousness. To prevent the 

 audience from being alarmed I observed that 

 it had often been my desire to receive acci- 

 dentally such a shock, and that my wish 

 had at length been fulfilled. But while ma- 

 king this remark the appearance which my 

 body presented to my eyes was that of a 

 number of separate pieces. The arms, for 

 example, were detached from the trunk, and 

 seemed suspended in the air. In fact, mem- 

 ory and the power of reasoning appeared 

 to be complete long before the optic nerve 

 was restored to healthy action. TYNDALL 

 Fragments of Science, vol. i, ch. 21, p. 442. 

 (A., 1900.) 



2677. POWER OF MIND OVER BODY 



Pain from Imaginary Wound. " A butcher 

 was brought into the shop of Mr. Macfarlan, 

 the druggist, from the market-place oppo- 

 site, laboring under a terrible accident. The 

 man, on trying to hook up a heavy piece of 

 meat above his head, slipped, and the sharp 

 hook penetrated his arm, so that he himself 

 was suspended. On being examined he was 

 pale, almost pulseless, and expressed him- 

 self as suffering acute agony. The arm could 

 not be moved without causing excessive pain, 

 and in cutting off the sleeve he frequently 

 cried out; yet when the arm was exposed, it 

 was found to be quite uninjured, the hook 

 having only traversed the sleeve of his 

 coat." BENNET The Mesmeric Mania of 

 1851, quoted by CARPENTER in Nature and 

 Man, bk. i, ch. 4, p. 158. (A., 1900.) 



2678. POWER OF MUSCLES IN- 

 STANTLY AVAILABLE Tension Maintained 

 in Rest. During rest or inactivity a mus- 

 cle has a slight but very perfect elasticity; 

 it admits of being considerably stretched, 

 but returns readily and completely to its 

 normal length. In the living body the 

 muscles are always stretched somewhat be- 

 yond their natural length; they are always 

 in a condition of slight tension, an arrange- 

 ment which enables the whole force of the 

 contraction to be utilized in approximating 

 the points of attachment. It is obvious that 

 if the muscles were lax the first part of 

 the contraction till the muscle became tight 

 would be wasted. BAKER Handbook of 

 Physiology, vol. ii, ch. 15, p. 22. (W. W., 

 1885.) 



2679. POWER OF QUIET PROCESS 



Simmering Water Cooks Food Effectually. 

 As a medium for heating the substances 

 to be cooked, simmering water is just as ef- 

 fective as " walloping " water. There are 

 exceptional operations of cookery, wherein 

 useful mechanical work is done by violent 

 boiling; but in all ordinary cookery sim- 

 mering is just as effective. The heat that 



is applied to do more than the smallest de- 

 gree of simmering is simply wasted in con- 

 verting water into useless steam. The 

 amount of such waste may be easily esti- 

 mated. To raise a given quantity of water 

 from the freezing- to the boiling-point de- 

 mands an amount of heat represented by 

 180 in Fahrenheit's thermometer, or 100 

 centigrade. To convert this into steam 990 

 F., or 550 C., is necessary just five and a 

 half -times as much. WILLIAMS Chemistry 

 of Cookery, ch. 2, p. 15. (A., 1900.) 



268O. 



The Spring vs. the 



Volcano. Altho the violent and paroxysmal 

 outbursts of volcanic mountains arrest the 

 attention, and powerfully impress us with 

 a sense of the volcanic activity going on 

 beneath the earth's surface, yet it may well 

 be doubted whether the quantity of heat 

 which the earth gets rid of by their means 

 at all approaches in amount that which is 

 quietly dissipated by means of the numerous 

 " stufas," gaseous exhalations, and thermal 

 springs which occur in such abundance all 

 over its surface. For while the former are 

 intermittent in their action, and powerful 

 outbursts are interrupted by long periods 

 of rest, the action of the latter, tho feeble, 

 is usually continuous. JUDD Volcanoes, ch. 

 8, p. 218. (A., 1899.) 



2681. POWER OF SLOW-MOVING 



MASS Glacier Plows Away Hill. The 

 snout of a glacier is potent to remove any- 

 thing against which it can fairly abut; and 

 this power, notwithstanding the slowness of 

 the motion, manifests itself at the end of 

 the Morteratsch glacier. A hillock, bearing 

 pine-trees, was in front of the glacier when 

 Mr. Hirst and myself inspected its end, and 

 this hillock is being bodily removed by the 

 thrust of the ice. Several of the trees are 

 overturned, and in a few years, if the gla- 

 cier continues its reputed advance, the 

 mound will certainly be plowed away. 

 TYNDALL Fragments of Science, ch. 9, p. 249. 

 (A., 1897.) 



2682. POWER OF THE INVISIBLE 



Energy of Molecules Their Rebound Turns 

 the Radiometer. The radiometer, to be seen 

 in almost every optician's window, was in- 

 vented by Sir William Crookes in 1873, and 

 consists of an exceedingly delicate windmill, 

 formed of four very slender arms supporting 

 thin metal or pith disks, one side of which 

 is blackened, the whole turning on a fine 

 central point, so as to revolve with hardly 

 any friction. The little machine is enclosed 

 in a glass bulb from which nearly all the air 

 has been extracted ; and when exposed to the 

 sun, or even to diffused daylight, the disks 

 revolve with considerable speed. At first 

 this motion was supposed to be caused by 

 the direct impact of the rays of light, .the 

 almost complete vacuum only serving to 

 diminish friction; but the explanation now 

 generally adopted is that the black surfaces 

 of the vanes, absorbing heat, become slightly 



