SULPHURATION. 



SUM, SUMMATION. 



910 



the Sicilian government, no longer daring to uphold the monopoly, 

 accepted the mediation of the king of the French in adjusting the 

 dispute with the British government. The monopoly was abolished in 

 July, 1840, and a mixed English and Sicilian commission was appointed 

 in November to investigate the claims of British subjects whose inte- 

 rests had been injured by it. The claims amounted to 65,6101., of 

 which 21,307/. was awarded ; and as it was stipulated that the awards 

 should bear interest at the rate of 6 per cent, so long as they remained 

 unsettled, the Sicilian government agreed, in January, 1842, to pay 

 them without any delay. The sulphur trade was thereupon placed on 

 the same footing as before the date of the contract with M. Tail. 



A correspondent of the Times newspaper, while noting and recording 

 the exploits of Garibaldi in Sicily in I860, turned aside to visit the 

 principal sulphur district, and to give an account of the present mode 

 of conducting the trade. The chief mines are at Villarosa, Santa 

 Catalda, and Terra di Falco. The sulphur lies imbedded in tufa, gyp- 

 sum, or limestone, mostly at the sides of mountains. Sometimes the 

 vein is so thick as to require pillars of sulphur to be left to support 

 the roof of the mine. The smelting, or preparation for market, used 

 to be conducted in the open air ; but as this injured the quality, and 

 moreover tainted the air of the neighbourhood, another plan is now 

 adopted. A round space is cleared on the side of a mountain, about 

 sixty feet in diameter, with a high wall to bound it on the outer or 

 lower side. An orifice in this side is formed, temporarily plastered 

 over. The sulphur-stone is placed in regular layers on the open space, 

 heaped up conically very high, and is well covered with the rubbish 

 resulting from former smeltings. Fire is applied through a small 

 opening, which is then closed up ; and the stone burns for about three 

 weeks, as much excluded from the air as possible. When the whole of 

 the sulphur in the stone has become liquefied, the hole is tapped, and 

 a black pitchy liquid runs out into troughs ; this liquid cools to a 

 yellow solid, clean or dirty according to its quality. The price of the 

 sulphur thus obtained is greatly increased by the difficulty of transport. 

 There is no road from the mines suitable for vehicles. Mules carry 

 the sulphur to the nearest town, whence it is conveyed in two-horse 

 carts to Girgenti. 



8ULPHUKATION, or SULPHURING, is the process of bleaching 

 employed to give whiteness to silk and woollens by exposing them to 

 the fumes of burning sulphur. For this process a detached chamber, 

 without a chimney, is made use of ; but so constructed that, when 

 required, a current of air may be passed through it. In sulphuring 

 silk, about 100 pounds, stretched on perches, are placed at a height of 

 nearly seven feet ; and about two pounds of sulphur, reduced to coarse 

 r, are put into an iron pot containing a small quantity of ashes ; 

 the sulphur is fired in several places, and the chamber well closed to 

 ut the loss of sulphurous fumes; afterwards the windows are 

 opened to let them escape and to dry the silk. In winter, after the 

 smell of the sulphurous vapour has ceased, the windows are shut, and 

 charcoal is burnt in the chamber, in order that the silk may be dried. 

 By this operation the silk becomes perfectly white, and is rendered fit 

 for subsequent oi>vrations. Woollen cloths are treated nearly in the 

 same manner. Straw hats and bonnets are also sulphured. 



srU'NUKETTED HYDROGEN. [Sr/LPHOB.] 



SU.NiriMc ACID. [Sui.i'iint.] 



..I' NITRIC ACID, Medical Properliet of. This, which is 

 regarded as the most potent of the mineral acids, is never taken 

 internally in a concentrated state except by accident, or with the 

 intention to commit suicide or murder. In such cases it acts as a 

 violent corrosive poison, causing complete disorganisation of the tissues 

 it comes in contact with, its course being obvious from the black and 

 charred state of the parts. This effect it is thought to produce from 

 its strong affinity to water, depriving the tissues of its elements, and 

 leaving the carbon free. This peculiarity distinguishes poisoning by it 

 from the other mineral acids. Notwithstanding the extensive destruc- 

 tion of iui[>ortant organs, such as the stomach, immediate death rarely 

 results from it, but the patient lingers sometimes for days, and in 

 some case* ultimately recovers. 



Sulphuric acid is sometimes employed in an undiluted state as a 

 caustic application to the bites of rabid animals, or to destroy warts or 

 portions of the eyelids in entropium and ectropium. 



In a considerably diluted state, if it be applied to the skin, it 

 occasions a painful impression, followed by numbness and a contraction 

 of the parts, anil even whiteness, owing to the diminished calibre of the 

 capillaries, lint shortly the atllux of blood to the part recurs, and 

 soon increases, so that the action of the vascular system appears to 

 become more developed than before. As it is presumable that a 

 similar series of actions takes place when received ill a diluted form 

 into the stomach, by bearing these phenomena in mind it is possible to 

 explain its therapeutic influence in many of the cases where it is 

 n - -i. 



Taken internally in a diluted but still strong state, it makes a 

 powerful impression on the stomach, followed by an instantaneous 

 sympathetic chill of the whole system : hence its power in checking 

 r rhage long before its particles can be received into the circula- 

 tion and constringe the vessels by immediate contact with their sides. 

 From the same cause it acts as a useful refrigerant in fevers and other 

 inflammatory dueue* when the animal temperature is too high. In 

 many of the transient diseases of the skin attended with much heat 



and itching, a solution of sulphate of magnesia, with an addition of 

 dilute sulphuric acid, quickly relieves them. It has also been given at 

 a late stage of typhus in some mild diluent, such as barley-water. In 

 combination with cinchona, it is of decided utility in purpura Itcemar- 

 rhayica. Nothing save oxide of zinc so certainly checks the colliquative 

 sweats which attend hectic fever as the compound infusion of roses. 

 In chronic diarrhoea and dysentery it is also sometimes of service. 

 Hicmorrhoidal 'fluxes are often restrained by its use. In some forms 

 of dyspepsia it is a valuable tonic, and may be longer persevered with 

 than any other mineral acid except phosphoric. In calculous diseases 

 with a phosphatic diathesis, it is much to be commended, from the 

 length of time it can be used. In such cases it is best given in 

 infusion of camomile made with cold water. It is employed largely 

 diluted as a gargle in the sore-throat of scarlet fever. Many cases of 

 cutaneous diseases have been cured by the internal use of sulphuric 

 acid. The aromatic sulphuric acid, called elixir of vitriol, has more 

 tonic properties than the simple acid. A few drops of it, ten or 

 twelve, in a cup of cold water, relieve very certainly the squeamishness 

 of the stomach which is felt iu the morning after an excess of wine. 

 In case of poisoning by sulphuric acid, lime-water, calcined magnesia, 

 or plaster from the wall, or a solution of soap, should instantly be 

 given. 



The mufiutUum dcidi tttlphurici is a most effectual application in 

 obstinate cases of itch. It chars the linen. 



SULPHURIC ETHER. [ETHYL.] 



SULPHUROUS ACID. [SULPHUB.] 



SL'LTA'N, an Arabic word meaning " a despotic ruler, or a man 

 who is the arbiter of the life and property of a set of men." It is the 

 usual title of royalty among the Arabs and Turks. From sulti'iu the 

 Italians have made their suldano, and the Spaniards have their aulldn. 

 The lawful wife of a sultan, who has children by him, is called by us 

 a sultana. 



SUM (in the sense of integral). Before the organisation of the 

 formal integral calculus, the isolated operations of integration which 

 were attained were expressed in words borrowed apparently from the 

 notion of indivisibles. [CAVALIERI, in BIOG. Div.] Thus the title of 

 one of Halley's papers is ' An Easy Demonstration, of the Analogy of 

 the Logarithmic Tangents to the Meridian Line or Sum of the Secants.' 

 Here the sum of the secants means what we should now denote by 



J sec x.dx. 



SUM AND DIFFERENCE. There is no need to define the 

 arithmetical meaning of these terms : a few words only are necessary 

 to put them in their proper position in algebra. When quantities 

 receive their proper algebraical signs, and those signs their interpreta- 

 tions [ALGEBRA ; SIGN ; &c.], they are said to, be added to a quantity 

 when they are allowed to produce their effect, and subtracted when 

 they are allowed to produce a contrary effect. And when quantities 

 are put together so that each produces its simple effect, they are said 

 to be added together ; while any parcel which is either withdrawn, or 

 compensated by others of equal and opposite effects, is said to be sub- 

 tracted. We are not here discussing principles, but settling terms ; 

 and it is enough if the notions appended to them be proper founda- 

 tions for clear and good deduction ; and an additional advantage if 

 common ideas and received phraseology be also suited, provided that 

 nothing be assumed from such ideas and phraseology to the prejudice 

 of the dependence of the deduction upon the prescribed definitions. 



To form a just idea of the property of any person, we take the sums 

 which he owes away from his assets ; that is, we take away, not his 

 debts, but sums out of his assets equal to his debts. To say that this 

 is taking away his debts would not be correct ; for taking away his 

 debts would be merely destroying his liabilities, without making his 

 assets answerable : a person who himself pays another's debts takes 

 them away. A court of justice which decides a claim against the 

 assets of any one, annexes or puts on a liability ; and this is in algebra 

 ii/'/i,/'/ . if the decision should be reversed on appeal, this liability to 

 pay is removed, and this is in algebra subtracting. In the phrase ' to 

 gain a loss," the word " gain" is used iu the preceding sense of simple 

 adjunction : if it were as common to talk of losing a loss, the verb to 

 lose would be used in the sense of to remove or to get rid of : the 

 other form of the word would be less of a bull, for to loose a loss would 

 be to detach it. In a third form, the idiom is still plainer ; to release 

 ! from] a loss would be precisely the idea of algebra, answering to sub- 

 tracting a loss. 



SUM, SUMMATION. In the articles INTEGRATION, FINITE, and 

 I'U(x;iiESSION, some ideas and rules are given upon the subject of the 

 summation, of a finite number of terms of a series ; and in KKHIKS 

 will be found examples of the inverse process of development. In the 

 present article we are to give some account of the methods of actual 

 summation which are in use in the higher branches of mathematics ; 

 referring for the demonstrations to the Differential Calculus in the 

 1 Library of Useful Knowledge' (cited by the letters D. C.). We shall 

 dwell upon this at greater length than would appear to be altogether 

 in keeping with the extent of the articles above cited ; the reason being 

 that many, persons to whom the following rules may be practically 

 useful never hear of them because they are locked up in Treatises on 

 the Differential Calculus, or in works which are not generally read. 

 The merest elements of differentiation and integration are enough to 



