SPE 



SP IT 



may express the material part, and is 

 then called the genus ; or the formal and 

 distinguishing part, and is then called 

 the differentia. Hence the genus and 

 differentia, taken together, constitute the 

 species ; e. g. " rational" and " animal," 

 constitute "man." 



1. Species in Natural History. Natu- 

 ralists employ the term "species" in a 

 technical sense, or ** second intention," 

 when applied to organized beings. In 

 this case it denotes such individuals as 

 are supposed to be descended from a com- 

 mon stock, or which might have so de- 

 scended; viz. which resemble one an- 

 other (to use Cuvier's expression) as 

 much as those of the same stock do. 



2. Species, in Mathematics. Euclid 

 employed the word • species' in its pri- 

 mitive sense of appearance : when the 

 form of a figure is given, he speaks of 

 the figure as given 'in species;' thus, 

 " rectilineal figures are said to be given 

 in species, which have each of their 

 angles given, and the ratios of their sides 

 given.'' 



3. The term species was employed by 

 Yieta in its logical sense, as opposed to 

 individual, in designating the algebraical 

 notation in those cases in which letters 

 were used for numbers in a general sense. 

 Thus he termed the logistics, or the sci- 

 ence of calculation, specious ; and, hence, 

 the language of algebra was, for some 

 time, called the specious notation. 



SPECIFIC. A term denoting any pro- 

 perty which is not general, but confined 

 to an individual or a species. 



SPECTRUM. This Latin term de- 

 notes an ideal form, and is applied to 

 certain optical phaenomena, described 

 under the term colours accidental ; and 

 to the effect of refraction on a ray of 

 light, explained under the word pris- 

 matic spectrum. 



SPECULAR. IRON ORE. Iron- 

 glance, or fer oligis I e of the French. A 

 sub-species of rhomboidal iron ore, com- 

 prising two varieties, viz. the common, 

 occurring in beds in primitive moun- 

 tains, and affording an excellent malle- 

 able iron ; and the micaceous, found in 

 beds in mica slate, and yielding an iron 

 well suited for cast ware. 



SPE'CULUM. The Latin term for a 

 looking-glass ; a name frequently given 

 to a mirror used for any scientific pur- 

 pose, as in a reflecting telescope. See 

 Mirror. 



SPECULUM METAL {speculum, a 

 looking-glass). An alloy of about two 

 310 



parts of copper and one of tin ; used for 

 making mirrors. 



SPEISS. An artificial arseniuret of 

 nickel, containing about 54 per cent, of 

 nickel. It collects at the bottom of cru- 

 cibles in which smalt or cobalt blue is 

 prepared. 



SPELTER. The name by which zinc 

 is known in commerce; but it usually 

 contains some lead and sulphur. 



SPERMATOCYSTI'DIUM {anep/jLa, 

 a seed, kvctk:, sl bladder). The name 

 given by Hedwig to the male organ of 

 mosses ; it is a pedunculated oblong sac, 

 containing a fluid mixea with a granular 

 pulp, which is discharged with some 

 force from the sac on the application of 

 water. By other writers these bodies are 

 called staminidia or antheridia. 



SPERMATO'PHORA (aTrep/xa, seed, 

 0fpcd, to carry). The cylindrical capsules 

 or sheaths in the cephalopods which con- 

 vey the sperm. They are also called the 

 moving filaments of Needham, their dis- 

 coverer. 



SPERMATOZO'A {airepixa, seed, 

 ^Mov, an animal). Zoosperms, or ani- 

 malcules found in the vas deferens and 

 the vesiculae seminales of animals, and, 

 it is said, in cryptogamic plants, and in 

 the pollen grains of the higher orders of 

 plants. 



SPE'RMODERM {(nrepixa, seed, 5ep- 

 fxa, skin). The testa, primine, or exter- 

 nal membrane of the seed of plants. The 

 term is sometimes applied collectively to 

 all the integuments of the seed. 



SPH^RE'NCHYMA (o-^alpci, a 

 sphere, e^x^y^f^^ any thing poured in). 

 Merenchijma. The name given by Mor- 

 ren to the spherical variety of the paren- 

 chyma of plants. 



SPHiEROSIDE'RITE. Sparry iron 

 ore. Carbonate of iron, occurring crys- 

 tallized, fibrous, massive, and botryoidal. 



SPH^'RULITE {acpaipa, a sphere, 

 Xido"}, a stone). A silicate of alumina, 

 occurring in small botryoidal and sphe- 

 roidal masses, imbedded in pitchstone, 

 in pearlstone, &c. 



SPHALERO-CA'RPIUM (<r0aAepof, 

 delusive, Kaprros, fruit). A botanical de- 

 signation of the collective fruit of the 

 yew, blitum, &c., described as an inde- 

 hiscent, one-seeded pericarp, enclosed 

 within a fleshy perianth. This is the 

 nux baccata of authors. 



SPHE'CIDiE Sphegides. A family 

 of hymenopterous insects of the section 

 Fossores, named from the typical genus 

 sphex, one species of which has been 



