INDEX. 



783 



476 ; superposition of small 

 effects, 476. 



Probable error, 555. 



Probability, etymology of, 197 ; 

 theory of, 197 ; principles, 200 ; 

 calculations, 203 ; difticulties of 

 theory, 213; ajiplieatioa of theory, 

 215 ; in induction, "219 ; injudi- 

 cial proceedings, 216 ; works on. 

 394 ; results of law, 656, 



Problems, to be worked by reader, 

 126 ; inverse problem of two 

 classes, 135 ; of three classes, 137. 



Proclus, commentaries of, 232. 



Proctor, K.A., star-diilr^s, 2i8. 



Projectiles, theory of, 466. 



Proper names, 27. 



Properties, generality of, 600 ; 

 uniform, 603 ; extreme instances, 

 607 ; correlation, 681. 



Property, logical, 699; peculiar,699. 



Proportion, simple, 501. 



Propositions, 36 ; negative, 43 ; 

 conversion of, 46 ; twofold mean- 

 ing, 47 ; disjunctive, 66 ; e(jui- 

 valeuce of, 115; identical, 119; 

 tautologous, 119. 



Protean verses, 175. 



Protoplasm, 524, 764. 



Prout's law, 263, 464. 



Provisional units, 323. 



Proximate statements, 144. 



Pyramidal numbers, 185. 



Pythagoras, on duality, 95; on the 

 number seven, 262, 624. 



QuAURic variation, 474. 



Qualitative, reasoning, 48 ; proposi- 

 tions, 119. 



Qnautilication of predicate, 41. 



Quantitative, reasoning, 48 ; [iro- 

 position.s, 119 ; questions, 278 ; 

 induction, 483. 



Quantities, continuous, 274 ; in- 

 commensurable, 275. 



Quaternions?, 160, 634. 



Quetekt, 183 ; ex[)erimiMit on pro- 

 bal)ility, 208 ; on mean and 

 average, 363 ; law of error, 378, 

 380 ; verification of law of error, 

 385. 



Radfan, 306. 

 Uadiant matter, 642. 

 liadiation of heat, 430. 

 KudioDiuter, 435. 



Rainbow, theory of, 526, 533. 



Rainfall, variation of, 430. 



Ramean tree, 703, 704. 



Ramsden's balance, 304. 



Rankine, on specific heat of air, 

 557 ; reconceutration of euerg\ , 

 751. 



Rational formula, 4S9. 



Rayleigh, Lord, on graphical 

 method, 495. 



Reasoning, arithmetical, 167 ; nii- 

 nierieally detinite, 168 ; geome- 

 trical, 458. 



Recorde, Robert, 15. 



Reduction, of syllogisms, 85 ; ad 

 absiirdmn, 415 ; of observations, 

 552, 572. 



Reflection, total, 650. 



Reflection, atmospheric, 340, 356, 

 500 ; law of, 501 ; conical, 540 ; 

 double, 685. 



Regnault, dilatation of mercury, 

 342 ; measurement of heat, 350 ; 

 exact experiment, 397 ; on Boyle's 

 law, 468, 471 ; latent heat of 

 steam, 487 ; graphical method, 

 494 ; specific heat of air, 557. 



Reid, on bifurcate classification,697. 



Reign of law, 741, 759. 



Rejection of observations, 390. 



Relation, sign of, 17 ; logic of, 22 ; 

 logical, 35 ; axiom of, 164. 



Repetition, method of, 287, 288. 



Representative hypotheses, 524. 



Reproduction, moaes of, 730. 



Reservation of ju'igiueiit, 592. 



Residual etfects, 558 ; phenomentu 

 560, 569. 



Resisting medium, 310, ."-23, 570. 



Resonance, 453. 



Reusch, on substitution, 21. 



Reversal, method of, 354. 



Revolution, quantity of, 306. 



Robertson, I'rof. Croom, 27, 101. 



Robison, electric curves, 446. 



Rock-salt, 609. 



Rccmer, divided circle, 355 : velocity 

 of light, 535, 



Roscoe, Prof, photometrical re- 

 searciie.s, 273 ; solubility of salts, 

 280 ; constant llame, 441 ; ab- 

 sorption of gases, 49'J ; vanadium, 

 52s ; atomic weight of vanadium, 

 392, 049. 



Rousseau on geometry, 233. 



Rules, of iiilereuce, 9, 17 ; indirect 



