CAS 



CAT 



the united margins, the ventral. See 

 Pistil. 



CARPO'LOGY (KapTTof, fruit, X^^oc, 

 description). That branch of botany 

 which treats of the structure of fruits. 



CARTESIAN DIVER. A well-known 

 glass figure, constructed so as to float in 

 a vessel of water above whose level a 

 small portion of air is confined in such a 

 manner t^at if this air be compressed, 

 the figure will immediately descend, and 

 rise again to the surface, when the pres- 

 sure ceases to be exerted. 



CARTE'SIAN PHILOSOPHY. A 

 system of mystical and pantheistic philo- 

 sophy introduced by Rene des Cartes. 

 According to him, consciousness is the 

 ground of all knowledge, and constitutes 

 the essence of the soul; its objects or 

 ideas are of three kinds — acquired, com- 

 pounded, and innate. All physical phe- 

 nomena are referred to vortices, or mo- 

 tions of matter, excited by the Author of 

 all things. Des Cartes was born in 1596, 

 and was contemporary with Lord Bacon. 



CA'RTHAMIN. A beautiful red pig- 

 ment, also called carthamic acid, pro- 

 cured from the flowers of the Carthamus 

 tinctorius or Bastard Saffron, and used 

 in silk dyeing. 



CARU'NCLE [caruncula, dim. of car o, 

 flesli)- A little piece of flesh; a soft 

 wart-like eminence ; an irregular protu- 

 berance of the testa about the umbilicus 

 of certain seeds. 



CARYOPHYLLA'CEiE. The Chick- 

 weed tribe of Dicotyledonous plants. 

 Herbaceous plants, with leaves opposite, 

 and tumid nodes ; flowers polypetalous, 

 symmetrical ; stamens definite ; ovarium 

 one-celled, with a free central placenta, 

 fruit a one-celled capsule, by obliteration 

 of the dissepiments. 



Carijophyllaceoiis Corolla. A corolla, 

 the petals of which have long, narrow, 

 and distant claws, as distinguished from 

 the alsinaceous corolla, in which the 

 petals are short and distant. 



CARYO'PSIS {Kctpvov, a nut, ox/^tf, 

 likeness). A one-celled, one-seeded, su- 

 perior, dry, inrlehiscent fruit, with the 

 integuments of the seed cohering insepa- 

 rably with the endocarp ; the character- 

 istic fruit of the Graminaceae. 



CASE {casus, a falling). This word is 

 used by grammarians, in its strict sense, 

 to signify a certain " variation in the 

 writing and utterance of a noun, denoting 

 the relation in which it stands to some 

 other part of the sentence." But it is 

 sometimes used to denote that relation 

 70 



itself, whether indicated by the termina- 

 tion, or by a preposition, or by its collo- 

 cation. Much confusion has arisen from 

 this ambiguity of the term. Whateiy. 



CASE-HARDENING. The process of 

 converting the external part of iron into 

 a coating of steel, by cementation for a 

 limited time. 



CA'SEIC ACID {caseus, cheese). An 

 acid extracted from cheese, and supposed 

 to contain many of the properties of this 

 substance. Casein or caseum is the curd 

 of the coagulable portion of milk, a prin- 

 ciple analogous to albumen. Caseous 

 oxide is another name for aposepedine, 

 a substance procured by the putrefaction 

 of animal matter. 



CASSI'DEOUS [cassis, ^YxQlmei). Hel- 

 met-shaped ; a designation of the irre- 

 gular corolla of aconitum and other 

 plants, in which one petal is very large 

 and hooded, or helmet-shaped. 



CA'SSINiE. Helmet-shells; a sub- 

 family of the Muricidt^, named from the 

 typical genus cassis, and characterized 

 by their large and often gigantic size. 



CAST IRON. A very variable mix- 

 ture of reduced substances, of which the 

 principal is iron combined with carbon. 

 The fused metal is run into channels 

 formed in sand, and thus cast into in- 

 gots or pigs. White cast iron, which is 

 the most definite variety, consists of four 

 atoms of iron and one atom of carbon. 



CASTOR or a GEMINORUM. A 

 star of the first magnitude in the head of 

 the Twins, being the nearer of the two to 

 the pole. 



CA'STORIDiE {castor, the beaver). 

 The Beaver tribe ; a family of the Ro- 

 dentia, comprising the beavers, voles, 

 lemmings, &c., and containing many 

 genera which closely resemble the rats. 



CAT'S EYE. A mineral, of a beautiful 

 appearance, brought from Ceylon. Its 

 colours are grey, green, brown, red, of 

 various shades. From a peculiar play of 

 light, arising from white fibres inter- 

 spersed, the name has been derived : the 

 French call the appearance chatoyant. 



CA'TACLYSM {KaraKXva/jio^, a flood). 

 A term applied by geologists to a deluge 

 or inundation. 



CATALOGUE OF THE STARS. A 

 table of the fixed stars, arranged accord- 

 ing to their right ascensions, or longi- 

 tudes, with their declinations, or latitudes, 

 together with their annual variations and 

 magnitudes. 



CATA'LYSIS {KaTci, downwards, \ua», 

 to loosen). Decomposition by contact. 



