incandescence 

 ncredulity 



SCIENTIFIC SIDE-LIGHTS 



light in these lectures the ends of two rods 

 of coke, rendered incandescent by electricity. 

 Coke is particularly suitable for this pur- 

 pose, because it can bear intense heat with- 

 out fusion or vaporization. It is also black, 

 which helps the light; for other circum- 

 stances being equal, as shown experimentally 

 by Professor Balfour Stewart, the blacker 

 the body the brighter will be its light when 

 incandescent. TYNDALL Lectures on Light, 

 lect. 6, p. 192. (A., 1898.) 



1612. INCLUSION VS. EXCLUSION 



Value of Each in Scientific Research 

 Newton United Caution and Intrepid- 

 ity. He [Sir Isaac Newton] wanted no 

 other recommendation for any one article 

 of science than the recommendation of evi- 

 dence and, with this recommendation, he 

 opened to it the chamber of his mind, tho 

 authority scowled upon it, and taste was 

 disgusted by it, and fashion was ashamed 

 of it, and all the beauteous speculation of 

 former days was cruelly broken up by this 

 new announcement of the better philosophy, 

 and scattered like the fragments of an aerial 

 vision, over which the past generations of 

 the world had been slumbering their pro- 

 found and their pleasing reverie. But, on 

 the other hand, should the article of science 

 want the recommendation of evidence, he 

 shut against it all the avenues of his un- 

 derstanding, and tho all antiquity lent their 

 suffrages to it, and all eloquence had thrown 

 around it the most attractive brilliancy, and 

 all habit had incorporated it with every 

 system of every seminary in Europe, and 

 all fancy had arrayed it in graces of the 

 most tempting solicitation, yet was the 

 steady and inflexible mind of Newton proof 

 against this whole weight of authority and 

 allurement, and, casting his cold and unwel- 

 come look at the specious plausibility, he 

 rebuked it from his presence. The strength 

 of his philosophy lay as much in refusing 

 admittance to that which wanted evidence 

 as in giving a place and an occupancy to 

 that which possessed it. CHALMERS Astro- 

 nomical Discourses, p. 48. (R. Ct., 48.) 



1613. INCOMPATIBILITY OF MEN- 

 TAL QUALITIES -Activity vs. Sensibility- 

 Intellect vs. Emotion Each Form of Great- 

 ness Has Its Own Sphere. Great activity 

 and great sensibility are extreme phases, 

 each using a large amount of power, and 

 therefore scarcely to be coupled in the same 

 system. The active, energetic man, loving 

 activity for its own sake, moving in every 

 direction, wants the delicate circumspection 

 of another man who does not love activity 

 for its own sake, but is energetic only at 

 the spur of his special ends. And, once more, 

 great intellect as a whole is not readily 

 united with a large emotional nature. The 

 incompatibility is best seen by inquiring 

 whether men of overflowing sociability are 

 deep and original thinkers, great discoverers, 

 accurate inquirers, great organizers in af- 

 fairs, or whether their greatness is not 



limited to the spheres where feeling performs 

 a part poetry, eloquence and social ascend- 

 ency. BAIN appendix to Conservation of 

 Energy by STEWART, p. 431. (Hum.) 



1614. INCREASE BY DESTRUCTION 



Gas Weighs More than the Coal Pro- 

 ducing It. A large part of the structure of 

 the earth's crust is formed of a substance 

 called limestone. Ordinary limestone is a 

 compound of common lime and carbon diox- 

 id, a gas that is found mixed with the air 

 to a very small degree. Carbon dioxid will 

 be better known by the older people as car- 

 bonic acid. It is a gas that is given off 

 whenever wood and coal are burned, or any 

 substance containing carbon. It is composed 

 of one atom of carbon to two of oxygen. 

 Every ton of carbon that is burned sends off 

 three and two-thirds tons of this gas. The 

 increase in weight comes from the fact that 

 every atom of carbon unites with two of 

 oxygen, which it takes from the air, and 

 the oxygen is heavier than the carbon. In 

 comparing the relative weights of atoms 

 (the smallest combinable particle of a solid, 

 liquid, or gas) we use the hydrogen atom 

 as the unit of comparison and call it " one," 

 because it is the lightest of all atoms. The 

 carbon atom is twelve times and the oxy- 

 gen atom sixteen times as heavy as the hy- 

 drogen atom. Hence it will be seen readily 

 how a ton of carbon will form three and 

 two-thirds times its weight of carbon di- 

 oxid. Lime, having a strong affinity or at- 

 traction for this gas, has absorbed it from 

 the air and water, forming what is known 

 as carbonate of lime, which is the ordinary 

 limestone. ELISHA GRAY Nature's Miracles, 

 vol. i, ch. 2, p. 12. (F. H. & H., 1900.) 



1615. INCREASE OF ANIMALS UN- 

 DER PROTECTION The South-American 

 Coypu Change of Habits Sudden Extermi- 

 nation. The coypu was much more abun- 

 dant fifty years ago than now, and its skin, 

 which has a fine fur under the long coarse 

 hair, was largely exported to Europe. About 

 that time the dictator Rosas issued a decree 

 prohibiting the hunting of the coypu. The 

 result was that the animals increased and 

 multiplied exceedingly, and abandoning their 

 aquatic habits they became terrestrial and 

 migratory, and swarmed everywhere in 

 search of food. Suddenly a mysterious mal- 

 ady fell on them, from which they quickly 

 perished, and became almost extinct. HUD- 

 SON Naturalist in La Plata, ch. 1, p. 12. 

 (C. &H., 1895.) 



1616. INCREASE OF EUROPEAN 

 CATTLE IN THE NEW WORLD Colum- 

 bus, in his second voyage, left a few black 

 cattle at Santo Domingo, and these ran wild 

 and increased so much that twenty-seven 

 years afterwards herds of from 4,000 to 

 8,000 head were not uncommon. Cattle were 

 afterwards taken from this island to Mexico 

 and to other parts of America, and in 1587, 

 sixty-five years after the conquest of Mexico, 



