IND 



INF 



not be divided). An object which is, in 

 the strict and primary sense, One, and, 

 consequently, cannot be logically divided ; 

 which is a metaphorical expression to 

 signify "'the distinct (i. e. separate) enu- 

 meration of several things signified by 

 one common name." This operation is 

 directly opposite to generalization, which 

 is performed by means of abstraction; 

 for as, in that, we lay aside the differences 

 by which several things are distinguished, 

 so as to call them all by one common 

 name, so, in Division, we add on the dif- 

 ferences, so as to enumerate them by their 

 several particular names. Thus "mine- 

 ral" is said to be divided into " stones," 

 " metals," &c. ; and metals again into 

 " gold," " iron," &c. ; and these are called 

 the parts, or members of the division. — 

 Whately. 



INDIVFSIBLES, METHOD OF. A 

 method formerly employed in Algebra, 

 founded on the assumption that quan- 

 tities are composed of infinitely small 

 quantities incapable of further division. 

 It was a kind of atomic theory, by which 

 lines were considered as made up of an 

 infinite number of points, surfaces of an 

 infinite number of lines, and solids of an 

 infinite number of surfaces. The method 

 has been entirely superseded by the dif- 

 ferential and integral calculus. 



INDU'CTION {induco, to bring in, to 

 infer). A kind of argument which in- 

 fers, respecting a whole class, what has 

 been ascertained respecting one or more 

 individuals of that class. Induction, so 

 far as it is an argument, may, of course, 

 be stated syllogistically ; but so far as it 

 is a process of inquiry with a view to ob- 

 tain the premises of that argument, it is, 

 of course, out of the province of logic ; 

 and the latter is the original and strict 

 sense of the word. — Whately. 



INDU'CTION (in Electricity). The 

 law by which an electrified body induces, 

 or tends to produce, in contiguous sub- 

 stances an electric state opposite to its 

 own. 



INDU'CTIVE SCIENCE. A science 

 which ascends from particular facts to 

 general principles, and descends from 

 these general principles to particular ap- 

 plications. Induction is the opposite of 

 hypothesis, which consists in laying down 

 a theory at the outset of an inquiry, and 

 trusting to future experiments, or ex- 

 ample, for its proof. 



INDUCTOMETER, DIFFEREN- 

 TIAL. An instrument, so named by 

 Faraday, consisting of three insulated 

 179 



metallic plates, placed parallel to, and at 

 equal distances from, one another, each 

 exterior plate being connected with an 

 insulated gold-leaf of an electrometer. 



INDUS. The Indian ; a modern south- 

 ern constellation, consisting of twelve 

 stars, situated between Sagittarius and 

 the South Pole. 



INDU'SIAL LIMESTONE. A fresh- 

 water limestone, abounding in the indu- 

 siae of the larva of phrygania, encrusted 

 by hard travertin and converted into 

 rock. 



INDU'SIUM {induo, to put on). A 

 term applied, in Botany, to that portion 

 of the epidermis of ferns which covers 

 the sori; also, to the peculiar form as- 

 sumed by the hairs of the style in certain 

 plants, when they are united into a cup, 

 enclosing the stigma, as in Goodeniaceae. 



INDU'VIiE {induvicB, clothes). In 

 Botany, this term denotes the withered 

 remains of leaves, which, not being arti- 

 culated with the stem, do not fall off, but 

 decay with it. A part so covered is said 

 to be induviate. 



INE'NCHYMA. A term applied by 

 Morren to the fibro-cellular tissue of 

 plants. 



INEQUA'LITY. 1. In Algebra, if 

 one quantity be greater or less than 

 another, or than nothing, and this be 

 expressed algebraically, it is called an 

 inequality. Thus x — a>6 — x is an 

 inequality, of which x — a forms one 

 side, and b — x the other. 2. In Astro- 

 nomy, the term denotes any deviation in 

 the motion of a planet or satellite from 

 its uniform mean motion. 



INE'RTIA {iners, inactive). That 

 property of matter by which it would al- 

 ways continue in the same state of rest 

 or motion in which it was put, unless 

 changed by some external force. The 

 quantity of matter of a body is deter- 

 mined by its quantity of inertia ; and 

 this is estimated by the quantity of force 

 required to put it in motion at a given 

 rate. 



IN ESSE; IN POSSE. The former 

 of these Latin terms is applied to things 

 which do actually exist; the latter, to 

 things which do not, but may, actually 

 exist. 



INFERENCE AND PROOF. " Rea- 

 soning comprehends Inferring and Prov- 

 ing ; which are not two different things, 

 but the same thing regarded in two dif- 

 ferent points of view : like the road from 

 London to York, and the road from York 

 to London. He who infers, proves ; and 

 16 



