SUL 6 



brittle, but when poured into water it is 

 whit nd viscid. Sulphur is of great 

 importance in the arts. It is used exten- 

 sirely in the manufacture of gunpowder 

 and of sulphuric acid. 



SCL'PHURATION. The name given to 

 the process by which woollen, silk, and 

 cotton goods and straw hats are exposed 

 to the vapours of burning sulphur or sul- 

 phurous acid gas, to whiten or bleach 

 them. The process requires the utmost 

 care. 



SUL'PHURET. A combination of sulphur 

 with a simple base. 



SUL'PHURETTED HYDROOEN. A delete- 

 rious gas composed of one part of hydro- 

 gen and 16 parts of sulphur, by weight. 

 It is the active constituent of the sulphu- 

 rous mineral waters. Its sp. gr. is 1191, 

 air being 1000. 



SUL'PHURETTED CHY'AZIC ACID. See 

 SULPHOCYAXIC ACID. 



SULPHU'RIC ACID. Oil of vitriol ; vitri- 

 olic acid. An acid which, when pure, is 

 without smell or colour, and of an oily 

 consistence. It is most violently caustic, 

 and so acid that a single drop of it will 

 give a gallon of water the power of red- 

 dening blue litmus. If four parts be 

 mixed with one of water at 50, the tem- 

 perature instantaneously rises to 300 F., 

 and the same quantity will raise one of 

 ice to 212. On the contrary, four parts of 

 ice, and one part of the acid sinks the ther- 

 mometer 4 below 0. The sulphuric acid 

 of Nordhausen is prepared by distilling 

 dried copperas : it comes over as a brown- 

 coloured liquid, varying in sp. gr. from 

 1'842 to 1-896. By redistillation in a glass 

 retort, into a receiver surrounded with 

 ice, it comes over in white fumes, and is 

 deposited in silky filaments, like asbes- 

 tos, tough and difficult to cut. This an- 

 hydrous acid consists of one equivalent 

 proportion of sulphur and three of oxy- 

 gen, or, by weight, 16 of the former and 

 24 of the latter. But the acid prepared 

 in this country by the combustion of sul- 

 phur with access of atmospheric air, is 

 colourless, and in its most concentrated 

 state has a sp. gr. of only T842 (though itis 

 sometimes found in commerce of a sp. gr. 

 of 1'845, in consequence of impurities). 

 In this state it contains 81J per cent, of 

 dry acid , and 100 parts of it are neutral- 

 ised by 143 of dry carbonate of potash, or 

 by 110 of dry carbonate of soda. The best 

 test for sulphuric acid in solution is the 

 hydrochlorate of baryta (the nitrate is 

 generally recommended). The salts 

 formed by the sulphuric acid with bases 

 are termed sulphates. 



SUL'PHCRIC ETHER. A highly volatile, 

 fragrant, inflammable, and intoxicating 

 liquid, produced by distilling a mixture 

 of equal weights of sulphuric acid and 

 alcohol. 



2 SUM 



SUL'PHUROUS ACID. "When sulphur is 

 heated to 180* or 190, in an open vessel, 

 it melts and soon afterwards emits a blu- 

 ish flame, visible in the dark, but which 

 in open day-light has the appearance of a 

 white fume. This fume has a suffocating 

 smell, and has so little heat that it will 

 not set fire to flax. The suffocating va- 

 pour given off is a gas composed of one 

 equivalent proportion of sulphur and two 

 of oxygen, or, by weight, of 16 of each: 

 it is sulphurous acid gas. It is, moreover, 

 readily imbibed by water, forming the 

 liquid formerly called volatile vitriolic acid, 

 and now sulphurous acid. It has a strong 

 sulphurous smell, but, when it is ex- 

 posed for a time to air, it loses this smell 

 by imbibing another atom of oxygen, and 

 is thereby changed into sulphuric acid. 

 The salts formed by the sulphurous acid 

 are termed sulphites. 



SULPHUR SALTS. This term is applied 

 to double sulphurets. The sulphurets of 

 the most electro-positive bases, such as 

 the protosulphurets of potassium, sodium, 

 &c., have been termed sulphur bases ; and 

 the sulphurets of arsenic, antimony, &c., 

 the bi-sulphuret of carbon, and sulphur- 

 etted hydrogen have been termed sulphur 

 adds. The compounds of one of the former 

 class with one of the latter are sulphur 

 salts. 



SCL'TAX, Arab, sultaun, mighty. A ge- 

 neral title of Mohammedan princes. 



SUMACH', ) Fr. sumac, Ger. schuniack, 



SHUMAC'. / Rus. swnak, Arab, su'mak, 

 from samak, to be red. The common su- 

 mach is the Rhus coriaria, a shrub which 

 grows spontaneously in Spain, Portugal, 

 the Bannat, and the Illyrian Provinc.es. 

 The young fustic is the Rhus cotinus, cul- 

 tivated in Italy ; and the ridoul or rodou 

 is the Coriaria myrthifolia, which grows 

 in the neighbourhood of Montpellier. 

 The shoots of these plants are cut yearly 

 quite to the root, and being carefully 

 dried, they are chipped or reduced to 

 powder by a mill, and are then prepared 

 for the purposes of dyeing and tanning, 

 and sold under the general name of su- 

 mach. The colouring matter is yellow. 



SUM'MER. 1. One of the four seasons of 



the year. 2. In architecture, any large 



timber supported on two posts, serving as 

 a lintel to a door, window, or the like. 

 SUM'MER-FALLOW. Naked Fallow. 

 Land ploughed, but lying bare of crop in 

 summer. 



SUM'MERSET. In gymnastics, a high 

 leap, in which the feet are thrown over 

 the head. The word is a corruption of the 

 French soubresaut. 



SUMMONS, Lat. nibmoneas. In law, a 

 citation to appear in court, to answer the 

 demand of the plaintiff. 



SUM'OOM. A pestilential wind of Per- 

 sia, &c- Set SIMOOX. 



