229 



FULCRUM. 



FUMIGATION. 



230 



theme, though they should never be very foreign to it. The overture 

 to the ' Zauberflb'te ' affords a splendid example of this species. The \ 

 Double Fugue consist* of two or more subjects moving together, and 

 dispersed among the different parts. Dorn. Scarlatti's in D minor is a j 



double fugue which has no superior of its kind. The first few bars 

 of this will more clearly explain than words can do the nature of so 

 elaborate a species of composition. 



Fugues of more than two subjects are classed, not very correctly, 



CT-fl j.j 



among double fugues; they are, however, rare, for which reason 

 perhaps they have never received a distinguishing name. Of these 

 the fugue of four subjects in the finale to Mozart's grand symphony in 

 C, and that of the same description in Handel's Altxander't mat, the 

 chorus ' Let Old Timotheus yield the prize,' are master-pieces of their 

 kind. All of this species must be considered as free fugues. The term 

 Fugue by Inversion requires little explanation. In this the theme is 

 inverted, as the name implies, but the effect arising out of such con- 

 trivance is appreciable only by those who know its difficulty, and 

 estimate its merit by the quantity of labour it has cost. In the Fugue 

 by Augmentation, the notes of the answer are doubled in length. In 

 the Fugue by Diminution, exactly the reverse takes place. There are 



other kinds of Fugue, but they are now almost forgotten, and it would 

 be useless to revive their names. 



Imitation is a species of fugue, and by theorists is generally treated 

 on previously to and as the precursor of the latter. As the word 

 indicates in this kind of composition, the theme is more or less 

 imitated in the different parts. It is not required, says Fux (Gradia 

 ad Parnaisum), that every note should be imitated, but only some 

 part of the subject; and Imitation is rather to take place in the 

 middle than in the commencement of a composition. It may be made 

 in any of the intervals, and in fact is governed by scarcely any rule. 

 The learned contrapuntist just named gives the following as ail 

 example of Imitation in the Unison : 



, 



The effect of technical imitation in music is unquestionably great ; it 

 is felt by all who have the slightest skill in the art, therefore employed 

 by all great composers of every school, ancient and modern. Canon, 

 which is sometimes called a perpetual fugue, may perhaps be admitted, 

 though cautiously, as part of a course of professional study, but should 

 rarely, if ever, be allowed to pass the boundaries of the school. 

 [CANON.] Fugue, but not of the pedantic or fantastic kind, should be 

 an object of serious attention with those who are ambitious of becoming 

 great composers, though in its severe form it ought to be almost 

 confined to cathedral music and to the oratorio, and is admissible there 

 only when introduced with great discretion, and guided by the hand 

 of an experienced sensible master. But without that which is here to 

 be understood by the term imitation or the recurrence, in some 

 shape, of the chief subject music in parts, of even a very simple kind, 

 loses one of its greatest beauties. Let it be used however with a view 

 solely to effect : if resorted to for the mistaken purpose of displaying 

 what a young or a dull composer may call his learning, imitation will 

 prove to be nothing better than mere plodding, and capable of exciting 

 no emotion except that which is the very reverse of pleasing. 



rri.cur.M. [LEVEK.] 



FULGURITE. [LIGHT.NINO ; and FULGEBITE in NAT. HIST. Div.] 



KI'LLING. [WOOLLEN MAM FACTURES.] 



FULMINATING MERCURY (HgO,, C.NjO,). The compound of 

 Pulminic A ml with mercury. It is prepared by dissolving 1 part of 

 mercury in 12 of nitric acid, sp. gr. 1'36, and then adding 11 parts of 

 1. sp. gr. '850. If a gentle heat be now applied by means of a 

 water-bath violent reaction ensues, metallic mercury is deposited, and 

 minute crystalline grains of fulminate of mercury separate, these must 

 be washed with cold water and dried at 100 Fahr. They explode 

 violently by percussion or heat, or by contact with sulphuric acid. 

 The preparation even of small quantities of fulminating mercury is 

 attended wtt >lile danger, ami ought not to be attempted by 



any one unacquainted with chemical manipulation. Mixed with six 

 times its weight of nitre it is used for priming percussion caps. 



FULMINATING SILVER (2AgO, C.N a O,). This salt of fulminic 

 acid i obtained by dissolving 1 grain of silver in 20 grains of nitric 

 acid diluted with 50 grains of alcohol. The remaining processes are 

 similar to those used for the preparation of fulminating mercury, than 

 which it i* still more dangerously explosive. [FULMINATING MERCUKY.] 



FULMINIC ACID (2HO, N S C,O.,). An acid which is isomeric 



with cyanic acid [CTASic ACID], that is, composed of the same 



nts in the same proportions, and they appear to have similar 



naturating powers. Fulminic acid has Hot yet been isolated, but it 



exist* in the detonating mercury and silver discovered by Mr. Howard. 



These iulintii.ttt.-H, as shown under the respective metals, are pro 



i Ity thr siinuli nM'Min action of nitric acid and alcohol upon 



th. -in : in this operation the metals are oxidized, and such porticmn of 



the carbon of the alcohol, and nitrogen and oxygen of the decomposed 



nitric acid combine, as to form the fulminic acid. Fulminic acid may 

 be separated from the oxides of silver and of mercury, and combined 

 with other bases, as with potash, and. it still retains its power of 

 forming detonating compounds. [CYANOGEN.] 



FULMINURIC ACID (HO, C. H, N s O t ), hocyanuric Add. A 

 recently discovered acid isomeric with cyanuric acid. The salts of 

 this acid are obtained by boiling the different fulminates with a solu- 

 tion of a soluble chloride. They crystallise generally with facility, 

 and explode feebly on the sudden application of heat. [CYANOGEN.] 



FUMARIC ACID. Buletic acid. This acid was first procured by 

 Braconnot from the l/ofcluspsmdo-iyntariitu by the following process : the 

 expressed juice is to be evaporated to the consistence of a syrup, and 

 then treated with alcohol, which leaves a white matter ; this is to be 

 washed with alcohol, then dissolved in water, and precipitated with 

 a" solution of nitrate of lead ; the precipitate diffused through water 

 is to be decomposed by sulphuretted hydrogen gas ; by evaporating 

 the remaining solution there are obtained impure crystals of futnario 

 acid, [and a very acid mother-water, composed of fuugic and phos- 

 phoric acids. The crystals of funiarie acid are redissolved in alcohol, 

 which leaves a calcareous salt, and by evaporating the solution purer 

 crystals of fuinaric acid are procured. Funiarie acid may also be 

 obtained by .submitting malic acid to heat, and it is also present in 

 Iceland moss, fumitory and other vegetables. 



Fuinaric acid is colourless, crystallises in four-sided prisms; itg 

 taste is acid, like that of bitartrate of potash ; it reddens litmus, does 

 not alter by exposure to the air ; is gritty, like sand, between the 

 teeth. It is soluble in 180 parts of water at 68, and in 45 parts of 

 alcohol. By heat the greater part of it is sublimed either in prismatic 

 crystals or in fine powder ; but towards the end of the operation 

 some empyreumatic oil is formed, and there is a strong smell of acetic 

 acid. It has the peculiar property of precipitating the peroxide of 

 iron from solutions, but not the protoxide. 



This acid forms salts with the alkalies and other bases; they are 

 called fumarates. They are not important compounds, none of them 

 being applied to any use. (Berzelius, ' Traite" de Chimie,' torn. 5, p. 102.) 



FUMARAMIDK (C.H.N.O,). When the fumarate of oxide of 

 ethyl, which is a heavy oily liquid, is acted on by ar/ita ammonia, it 

 forms a white insoluble powder, which iaftaniiramidc, and possesses all 

 the characters of a compound amide. 



FUMARIMIDE (C,H.,N0 4 2). A reddish amorphous powder, formed 

 by exposing bimalate of ammonia to a heat of about 400 Fahr. Heated 

 for several hours with hydrochloric acid, it yields aspartic acid. 



Aspartic acid. 



FUMIGATION is the application of the vapour or fumes from me- 

 tallic or other preparations to the body, with the intention of healing 



