CON 



CON 



together with the fourth, is to the fourth. 

 See Force. 



COMPOSFTION, FALLACY OF. A 

 logical fallacy, in which the middle term 

 is used in one premiss collectively, in the 

 other distributively. The form in which 

 it is most usually employed, is to esta- 

 blish some truth, separately, concerning 

 each member of a certain class, and 

 thence to infer the same of the whole 

 collectively. Thus, it may be argued that, 

 because it is not very improbable that 

 a person may throw sixes in any one out 

 of a hundred throws, therefore it is no 

 more improbable that he may throw 

 sixes a hundred times running. Whately. 



COMPOUNDS. The following terms 

 are employed in designating compounds : 



1. Binary, ternary, quaternary. These 

 terms refer to the number of elements or 

 proximate principles— two, three, or four 

 — which exist in a compound. The binary 

 compounds of oxygen, chlorine, iodine, 

 bromine, and fluorine, which are not 

 acid, terminate in ide, as oxide, chloride, 

 &c. ; those of all other substances termi- 

 nate in uret, as hydruret of carbon, sul- 

 phuret of iron, &c. 



2. Bis, ter, quater. These are Latin 

 numerals, indicating the number of atoms 

 of acid, which are combined with one of 

 the base in a compound, as 6i-sulphate of 

 soda, &c. 



3. Dis, iris, tetrakis. These are Greek 

 numerals, indicating the number of atoms 

 of base, which are combined with one of 

 the acid in a compound, as c?i-chromate 

 of lead, &c. No prefix is used when the 

 compound consists of one atom of each 

 ingredient. But there are many excep- 

 tions to these rules : protoxide and deut- 

 oxide are frequently used for oxide and 

 bin-oxide respectively. 



COMPRESSIBI'LITY {comprimo, to 

 compress). A property of masses of mat- 

 ter, by which their particles are capable 

 of being brought nearer together. Bodies 

 which recover their former bulk on re- 

 moval of the compressing cause, are 

 called elastic. 



CO'MPTONITE. A mineral found in 

 drusy cavities, in ejected masses, on 

 Mount Vesuvius ; first brought to this 

 country by Lord Compton, in 1818. 



CONCENTRATION. The strengthen- 

 ing of solutions or mixtures by evapora- 

 tion of their watery parts. 



CONCE'NTRIC. Having the same 



centre, as applied to circles which are 



described about the same point, to the 



striae of bivalves which run parallel to 



87 



the margin, &c. The concentric theory 

 is the theory of epicycles, as opposed to 

 the eccentric theory. See Epicycle. 



CONCEPTA'CULUM. Literally, a 

 receptacle ; a term applied, in Botany, to 

 a species of compound fruit, which is two- 

 celled, many-seeded, superior, separating 

 into two portions, the seeds of which 

 detach themselves from their placenta, 

 and lie loose in the cavity of each cell. 

 This fruit occurs in Asclepias, and is also 

 called the double follicle. 



CONCH A'CEA (/<67xn, a shell). A 

 family of conchiferous molluscs, in De 

 Blainville's arrangement, corresponding 

 with Cuvier's Cardiacese, or the Cockle 

 tribe. See Cardiacece. 



CONCHPFERA {concha, a shell, fero, 

 to carry). A class of the Mollusca, com- 

 prising acephalous aquatic animals, co- 

 vered with a bivalve or multivalve shell. 

 There are two orders, viz. — 



1. Monomyaria, in which the shells 

 are narrow longitudinally, and have but 

 one muscular impression on the valve, 

 as in the spondylus. 



2. Dimyaria, in which the shell is ex- 

 tended longitudinally, and has two mus- 

 cular impressions on the valve, as in the 

 area barbata. 



CONCHOID [KO'txoeibij^, resembling 

 a shell). The designation of a curve, 

 employed by Nicomedes for finding the 

 two mean proportionals, and the dupli- 

 cation of the cube. 



CONCHO'LOGY (k^yx^. a shell, A6709, 

 a description). The '* art " of arranging 

 the shells of testaceous animals, without 

 reference to the animals which they con- 

 tain. See Malacology. 



CONCLU'SION. In Logic, the propo- 

 sition which is inferred from the premises 

 of an argument. 



CO'NCORD. A term applied in Music 

 to two combined sounds which are uni- 

 versally agreeable to the ear. The 8th, 

 or octave, and the 6th are called perfect 

 concords, because as concords they are 

 not liable to alteration by flats or sharps ; 

 the 3rd and 6th are termed imperfect con- 

 cords, because alterable. 



CONCRETE. A term denoting a qua- 

 lity accompanied with its particular sub- 

 ject, as opposed to abstract, which de- 

 notes the quality without its subject. 

 The names of classes are abstract, those 

 of individuals concrete; and from con- 

 crete adjectives are made abstract sub- 

 stantives. See Abstract. 



CONCRETIONARY DEPOSITS. In 

 Geology, a designation of those Recent or 



