S A L 



SAP 



colour ; and Poikilitic System, from the 

 varied colours of its rocks. 



SALIFIABLE BASE {sal, a salt, fio, 

 to become). A substance which forms 

 definite compounds with an acid, and 

 which, when liquid, or in a state of solu- 

 tion, has ah alkaline reaction. The acid, 

 of whatever kind, was denominated by 

 Lavoisier, the salifying principle. 



SALMO'NlDiE {salmo, the salmon). 

 The Salmon and Trout tribe ; a family of 

 Malacopterygious or soft-spined fishes, 

 distinguished by the fatty deposition in 

 the dorsal fin, from part of which the 

 spines often disappear. 



SA'LPIANS. An order of the tuni- 

 cated mollusca, which float in the open 

 sea, and are characterized by their trans- 

 parent elastic outer tunic, which is elon- 

 gated, compressed, and open at both ex- 

 tremities. The order is named from a 

 kind of fish called salpe. 



SALT. A general term in Chemistry 

 for a combination of binary compounds 

 with each other, as of sulphuric acid 

 with soda in Glauber's salt ; such a com- 

 bination is called a ternary compound, 

 and it is thus distinguished from binary 

 compounds, in which one element is 

 combined with another element; and 

 from quaternary compounds, in which 

 salts or double salts, such as alum, are 

 combined together. 



1. Nomenclature of Salts. Salts are 

 named according to the acid they con- 

 tain, the termination ic of the acid being 

 changed into ate, and that of ous into 

 ite. Thus a salt of sulphuric acid is a 

 sulphate; of sulphurous acid, Bisulphite; 

 &c., and the name of the oxide indicates 

 the species, as the sulphate of the oxide 

 of silver, or simply the sulphate of sil- 

 ver, the oxide of the metal being always 

 understood. 



2. A «Mper-s ulphate contains a greater 

 proportion of acid than the sulphate or 

 neutral sulphate ; a 6»-sulphate twice as 

 much, and a se^gMi- sulphate once and a 

 half as much as the neutral sulphate; 

 while a ^wft-sulphate contains a less pro- 

 portion than the neutral salt ; the pre- 

 fixes referring in all cases to the propor- 

 tion of acid in the salt, or to the electro- 

 negative ingredient, as in the case of 

 oxides. 



3. The excess of base in sub-salts is 

 sometimes indicated by Greek prefixes 

 expressive of quantity, as di-chromate 

 of lead, ^r/*-acetate of lead ; but this 

 deviation from rule is apt to lead to con- 

 fusion. If a precise expression for such 



294 



sub-salts were required, it would be 

 better to say, the bibasic subchromate of 

 lead, the tribasic subacetate of lead. 

 But the names of both acid and basic 

 salts are less in accordance with correct 

 views of their constitution, than the 

 names of any other class of compounds. 

 — Graham. 



SALT SPRINGS. Springs of water 

 containing a large quantity of common 

 s^lt. They abound in Cheshire and 

 "Worcestershire, and culinary salt is ob- 

 tained from them by mere evaporation. 



SALTATO'RES {salto, to leap). A 

 family of Spiders which make no web, 

 but spring upon their prey by insidious' 

 and agile leaps. 



SALTATO'RIA {salto, to leap). A 

 family of Orthopterous insects, in which 

 the thighs of the hind legs are much 

 larger than the rest, by which they pos- 

 sess great powers of leaping. They in- 

 clude the crickets, grasshoppers, locusts, 

 &c. See Cursoria. 



SALTPETRE. Sal petres. Nitre, or 

 the nitrate of potash. It occurs native 

 as efiiorescence, mixed with other ni- 

 trates, and as crystalline crusts. 



SA'MARA. The botanical designa- 

 tion of a two or more-celled superior 

 fruit, bordered by wing-like expansions, 

 as in sycamore. 



SAME. This term, as well as " One," 

 "Identical," and their derivatives, is 

 ambiguous, and has led to much error in 

 philosophy. In its primary sense it de- 

 notes identity, and does not admit of 

 degrees; in its secondary sense it is 

 employed to denote great similarity, and, 

 in popular usage, admits of degrees, as 

 when we speak of two things being 

 nearly the same, but not entirely. To 

 this ambiguity Whately refers much of 

 the error of Realism ; of Plato's theory 

 of Ideas ; of the personifications and dei- 

 fications in poetical mythology ; &c. 



SA'NDIVER. Glass gall. A saline 

 substance, which rises as a scum in 

 vessels employed in the manufacture of 

 glass. 



SANDSTONE. Any stone which is 

 composed of agglutinated grains of sand, 

 whether calcareous, siliceous, or of any 

 other mineral nature. The chief ingre- 

 dient of sand is granular quartz or flint. 



SA'NIDINE. Glassy felspar; this, 

 and ice-spar, are substances nearly allied 

 to common felspar. 



SAP. The ascending limpid juice of 

 plants, as distinguished from the de- 

 scending or elaborated juice. 



