INDEX. 



473 



Conservation of energy, ii. 83, 431. 



Constant numbers, i. 380 ; mathemati 

 cal, 381 ; physical, 383; astronomical, 

 384 ; terrestrial, 385 ; organic, 385 ; 

 social, 386. 



Continuity, sense of, ii. 117; detection 

 of, 262; law of, 268, 419; failure of, 



273- 



Continuous quantity, ii. 108. 



Contrapositive propositions, i. 100, 101. 



Conversion, i. 55 ; contrapositive, 97. 



Copernican theory, i. 283 ; ii. 153, 281, 

 298, 310. 



Copula, i. 19. 



Corpuscular theory, ii. 150, 173, 304. 



Correction, method of, i. 406. 



Correlation, ii. 350, 354. 



Cotes, Roger, means, i. 416 ; method 

 of least squares, 437 ; weighted ob 

 servations, 450. 



Couple, mechanical, ii. 318. 



Creation, i. i 70 ; ii. 416. 



Crystallography, i. 153; ii. 162, 184, 



3&quot;. 3i9. 359. 39 8 &amp;gt; 45 ; . 

 Crystals, pseudomorphic, ii. 324. 

 Curves, nature of, ii. 99 ; discovery of, 



11 5- 



Cuvier, {.355; ii. 31. 

 Cyanite, ii. 261. 

 Cycloid, ii. 291. 



D. 



D Alemberfc, probability, i. 244, 245 ; 

 gravity, ii. 81. 



Dalton, laws of, ii. 82, 91, 274, 329. 



Darwin, Charles, theory, ii. 8, 48, 165, 

 218, 405, 421; orchids, 19, 409; 

 classification, 410 ; reproduction, 421. 



Davy, Sir H., instruments, i. 313 ; heat 

 of friction, i. 397 ; ii. 23 ; electro 

 lysis, 29, 38. 



Decandolle s system, ii. 387. 



Deduction, i. 13,59; probable, 239. 



Definition, i. 64; ii. 397. 



De la Rue, ii. 67, 109. 



De Morgan, sign of equality, i. 18; 

 Aristotle s logic, 22 ; relatives, 27 ; 

 limited universe, 52 ; complex pro 

 blems, 90 ; contrapositive conversion, 

 97 ; Euclid s indirect proof, 98 ; 

 logical problems, 116; error of S3 7 s- 

 tem, 135 ; numerically definite syllo 

 gism, 190 ; probability, 226; experi 

 ments on probability, 237; probable 

 argument, 239 ; trisection of angle, 

 268 ; finite exporience, 300 ; arcual 

 unit, 358; personal error, 403 ; means, 

 419; average, 421 : weighted obser 

 vations, 450 ; works on probability, 

 459! apparent sequence, ii. 1 3 ; small 

 errors, 101 ; subequality, 102; gene 

 ralisation, 249 ; catalogues, 403. 



Density, unity of, i. 371 ; of earth, ii. 

 207 ; negative, 304. 



Depth of oceans, i. 347. 



Descartes, ii. 135, 290. 



Development, logical, i. 104. 



Diagnosis, ii. 394. 



Diamond, ii. 159, 261. 



Diatomacese, ii. 9, 410. 



Difference, law of, i. 6, 87, 95 ; sijj;n of, 

 20,54; of numbers, 2 10 : calculus of, 

 ii. 122 ; logical, 377. 



Differential calculus, ii. 99 ; thermo 

 meter, i. 400. 



Diffraction of light, ii. 27. 



Discontinuity, ii. 274. 



Discoveries, accidental, ii. 162 ; pre 

 dicted, 171. 



Disjunctive terms, i. 79 &amp;gt; conjunction, 

 80; proposition, 89, 127; syllogism, 

 92. 



Donkin, i. 226, 227, 243, 248. 



Double refraction, ii. 174, 23 r, 361. 



Dove s law, ii. i6S. 



Draper s law, ii. 257. 



Duality, law of, i. 87, 95. 



Duration, i. 360. 



E. 



Eclipses, i. 343 ; ii. 322. 



Electric acid, ii. 38. 



Electricity, ii. 163, 187, 237, 264; unit 



of, i. 379 : theory of, ii. 154. 

 Electrolysis, ii. 37, 163. 

 Electro-magnetism, ii. 164. 

 Electrometer, i. 330. 

 Elements, classification of, ii. 347, 349&amp;gt; 



3^4. 374- 



Ellicott, on Clocks, ii. 70. 



Ellipsis, logical, i. 69. 



Elliptic variation, ii. 94. 



Ellis, A. J., i. 27, 190, 194. 



Ellis, W., effect of full moon, ii. 14. 



Emanation, law of, ii. 82. 



Emotions, ii. 424. 



Empirical knowledge, ii. 132, 157, 158 ; 

 measurements, 190. 



Encke, Comet, i. 363 ; ii. 212; law of 

 error, i. 445 ; mean, 449 ; resisting 

 medium, ii. 155. 



Energy, unit of, i. 376 ; conservation 

 of, ii. 83, 431. 



Equality, i. 56, 183; sign of, 18 ; 

 meanings of, ii. 102. 



Equations, i. 142, 180; ii. 51. 



Equilibrium, unstable, i. 320 ; ii. 319. 



Equivalence, logical, i. 132, 134 ; re 

 markable case of, 162 ; ii. 323. 



Eratosthenes, sieve, i. 96, 141, 160; on 

 latitude, 315, 342. 



Error, function, i. 382 ; avoidance of, 

 3935 personal, 402; rules fur elimi 

 nating, 409 ; law of, 434 ; formula of, 



