CUM 



CUR 



which involves the cube, or third power 

 of the unknown quantity. Like equations 

 of any other degree, cubic equations are 

 either pure or adjected. 



CUCULI'DiE [cuculus, a cuckoo). The 

 Cuckoo tribe ; a family of the Scansores, 

 or Climbing birds, characterized by the 

 short and slender structure of the feet, 

 and by their migratory habits. Mac- 

 gillivr'ay places them next to the goat- 

 suckers, from the great similarity of their 

 digestive organs. They are little capable 

 of walking, and belong to a group, of 

 which the habit is to perch on trees or 

 shrubs, whence they glide after passing 

 insects. 



CUCU'LINiE. A family of bees which, 

 having no femoral plates for transporting 

 pollen, resort to the combs of other bees 

 in order to deposit their eggs— a habit 

 resembling that of the cuculus, or cuckoo. 

 CUCU'LLATE {cucullus, a hood). 

 Hooded ; having the apex and sides 

 curved inward, as the upper sepal of 

 aconite. 



CUCURBITA'CEiE ( cucurbita, a 

 gourd). The Gourd tribe of Dicotyle- 

 donous plants. Climbing plants with 

 leaves palmated, succulent ; flowers uni- 

 sexual, monopetalous ; stamens cohering 

 in three parcels ; ovarium inferior ; fruit 

 fleshy ; seeds flat ; testa coriaceous. 



CUDBEAR. A neutral colouring mat- 

 ter, prepared from the Leconora tartar ea 

 and other lichens, and named from Sir 

 Cuthbert Gordon. The Germans call it 

 persio. 



CULFCID^ {culex, a gnat). The 

 Gnat tribe ; a family of Dipterous in- 

 sects, belonging to the section Nemocera, 

 distinguished by their beautifully tufted 

 antennae. 



CULM. The peculiar stem of grasses, 

 sedges, &c. Also, a provincial synonym 

 of anthracite. 



CULMINA'TION {culmen, the top of 

 any thing). The transit or passage of a 

 star over the meridian, or the point of its 

 highest altitude. 



CU'MBRIAN GROUP. A group of 

 rocks constituting the lower series of the 

 Clay-slate system, upwards of 3000 feet 

 in thickness, and comprising the horn- 

 blendic clay-slate, chiastolite-slate, and 

 clay-slate. 



CUMULO'STRATUS. The twain- 

 cloud; a composite modification of clouds, 

 known by its generally flat base, with a 

 superstructure resembling a bulky cumu- 

 lus overhanging the base in large fleecy 

 protuberances, or rising into the forms 

 96 



rocks and mountains. The Latin term 

 is derived from the frequent grouping of 

 considerable cumuli, or masses, upon a 

 common stratum, or base; the English 

 term, from the frequently visible coales- 

 cence of two other modifications, viz. the 

 cirrus and the cumulus. This cloud 

 may always be regarded as a stage to- 

 wards the production of rain or snow, 

 and, in this case, it always ends in the 

 nimbus. 



CU'MULUS (Lat. aheap). The stacJcen- 

 cloud ; a primary form of clouds, known 

 by its irregular hemispherical or heaped 

 superstructure, and usually flattened 

 base. It is formed by the gathering 

 together of detached clouds, which then 

 appear stacked into one large and ele- 

 vated mass. It may be called the cloud 

 of day, as it usually exists only during 

 that period. 



CUMY'L. The compound radical of a 

 series of compounds procured from the 

 seeds of the Cuminum Cyminum. 



CU'NEIFORM {cuneus, a wedge,/ormo, 

 likeness). Cuneate. Wedge-shaped ; in- 

 versely triangular, with rounded angles ; 

 a shape characteristic of certain bivalves, 

 analogous to the clavate form among uni- 

 valves. 



Cuneiform Letters. A term applied 

 to the inscriptions found on old Baby- 

 lonian and Persian monuments, from 

 the characters being formed like a 

 wedge. 



CUPEL {kuppel, German). A small 

 flat cMp-like crucible, made of bone ash, 

 used in the assays of the precious metals, 

 which are fused on a cupel with lead. 



CUPELLA'TION. The process of pu- 

 rifying gold and silver by melting them 

 with lead, which becomes flrst oxidated, 

 then vitrified, and sinks into the cupel, 

 carrying along with it all the baser 

 metals, and leaving the gold or silver 

 upon its surface. 



CU'PULA. A form of involucrum, 

 occurring in the oak, the beech, the 

 hazel ; and consisting of bracts not much 

 developed till after flowering, when they 

 cohere by their bases, and form a kind 

 of cup. 



CUPULI'FERtE {cupula, a small cup). 

 The Oak tribe of Dicotyledonous plants. 

 Trees or shrubs with leaves alternate ; 

 ^oz^<?r5 amentaceous, dioecious, apetalous; 

 ovarium inferior, inclosed in a rupule ; 

 fruit a horny or coriaceous nut. 



CU'RCUMA PAPER. Paper stained 

 with a decoction of turmeric, and em- 

 ployed by chemists as a test of free alkali, 



