ACCUSATIVE CASK 



ACETATE. 



quantity of motion obtained by an exertion of muscular power. Thus 

 a imitb, when he would strike on an anvil with the greatest force, 

 add* to the power of gravity on the hammer the accumulation 

 of velocity arUing from a whirling motion, in a vertical plane, 

 which he girea above hi* head to the hammer before he allow* it to 



In the old coining-machines which, like those at present used, pro- 

 duced the impression on the metal by the power of a screw, a great 

 accumulation of force was obtained by causing a number of men to 

 turn the horizontal bars attached to the vertical shaft which carried 

 the screw : by the pi-ensure of the men against the bars, while 

 several revolutions were matte about the axis of the screw, an accele- 

 ration of motion during that time took place ; and the accumulation 

 was instantaneously spent upon the metal, in aid of the pressure 

 arising from the power of the screw alone. The like accumulation of 

 force is obtained, but far more efficiently, in the coining-press of the 

 present day by means of its fly-wheel ; the reciprocating motion of a 

 piston connected with a steam-engine communicates, by means of a 

 crank, a continuous movement to the fly, and at the same time, a 

 reciprocating rectilinear motion vertically to the cylindrical shaft (the 

 stamper), on which the screw is formed. With half a revolution of 

 the fly-wheel the stamper is lifted up. and with the other half it is 

 forced down upon the metal. 



When a fly-wheel is acted on by any prime mover, as wind, water, 

 or steam, its motion continually accelerates, and a corres|ionding ac- 

 celeration is induced in the wheel-work, in rollers, or in the stampers 

 with which it is connected : the resistance to be overcome at what 

 is called the working point destroys however this acceleration, and 

 would allow the movement to be uniform, if it were not for the 

 temporary accelerations or retardations which are caused by variations 

 in the intensity of the moving power, or iu the amount of the 

 resistance ; and these are almost wholly counteracted by the accumu- 

 lated power which constantly exists in the fly. 



ACCUSATIVE CASE, a term used in the grammatical system of 

 the Latin language, and thence unnecessarily introduced into that of 

 the English language. In Greek this case is not called acrutatirc, but 

 the same idea is expressed by a corresponding term in that language. 

 In the article ablatire cate, the meaning of the word rate was explained. 

 In that article it was seen that the little syllable em is attached to the 

 end of Latin nouns, and has the meaning of motion to. But where the 

 simple Latin noun terminated in a vowel, the e of em was absorbed by 

 that preceding vowel. Thus, to take an example, Roma was, and is, 

 the name of the Roman capital, though, by Englishmen, generally cor- 

 rupted into Some ; consequently, to Rome was expressed by Romam (a 

 contraction from Roma-em) ; so, I'M Romam, expressed into Rome. In 

 Roma, without the m, would signify merely in Rome. The accusative 

 then signifying originally the object to which any motion is directed, 

 was afterwards by a very natural metaphor, employed to distinguish 

 the object of any action or feeling ; thus, inctndere Romam, to burn 

 Rome, The Spanish and Portuguese have, in their languages, very 

 closely imitated the Latin in this respect : dapidio de m cam & mi 

 Dulfinea if translated word for word would be he despatched from 

 his house to my Dalrinea ; but nothing more is meant than what we 

 express by he despatched my Dulcinea from his house. The despatch- 

 ing is with reference to Dulcinea, The employment of the letter m, 

 with or without a weak vowel before it, occurs likewise in the Sanscrit 

 language ; and indeed in our own, in the pronouns Aim and tchom, 

 from lie and vhn. The Greeks preferred the allied letter n, which is 

 also found in some classes of the German nouns, as den lira fen, the 

 Count, from the nominative <lrr Graf. When the term amuativc fate 

 is used in the grammar of our own language, it is only in this second 

 or metaphorical sense, and, consequently, it is equivalent to what many 

 grammar* call by the better name of the olijectire rate, or more simply 

 the objrct. 



ACETAL. (Formula, C,,H 14 4 .) A compound first formed by 

 Dobereiner, and called by him oxygenated ether. It is produced by 

 the alow oxidation of alcohol under the influence of platinum black. 

 A number of watch-glasses containing platinum black, slightly moistened, 

 ore to be suspended in a tall wide-mouthed jar or bottle, and near the 

 surface of some alcohol which must cover the bottom to the depth of 

 about an inch. After the bottle has been left for two or three weeks 

 in a warm place, it will be found to contain on acid liquid consisting of 

 acetal, alcohol, aldehyde, and acetic ether. This is to be neutralised 

 with carbonate of ]iotash, as much chloride of calcium as will dissolve 

 is to be added, and the whole subjected to distillation. The first fourth 

 only of the product is to be collected, and chloride of calcium again 

 added. A thin oily fluid rises to the surface, which is acetal, mixed 

 with the before-mentioned impurities. Repeated treatment with 

 chloride of calcium, at a gentle heat, in a retort, expels the aldehyde ; 

 caustic potash decomposes the ether, and washing with water rcin'..\e, 

 the alcohol. After once more rectifying from chloride of calcium, the 

 acetal U pure. 



Acetal is a limpid colourless liquid, of an agreeable ethereal odour, 

 and a taste resembling that of filberts. Its sp. g. is "825, that of iU 

 vapour 4-24. It boils at 221, is soluble In about 18 parts of cold 

 water, and miscible with alcohol and ether in all proportions. Oxidising 

 agents convert it into aldehyde and then into acetic acid. In contact 

 with the air, alc<5holic solutions of the alkalies convert it into nldehydic 



resin. It may be considered M a compound of 2 eq. of oxide of othvle 

 (ether) with 1 eq. of aldehyde. 



Ether. AldrhTd*. 



IC.H.O, + C.H.O, =C, H,,0.. 



and, consequently, its formation from alcohol may be thn- 



SSI* 



+ C.H.,0, 



0,1 .,IM 

 II J 4 -JI I 



Alcohol. 



ActUl. 



ACETAMIDK. 



ACETANALIDE. [Asmm] 



ACETATE. A salt arising from the displacement of the 

 acetic acid, HO, C.H.O,, by a bane. Alkaline acetates and acetate* of 

 the alkaline earths may be formed liy decomposing their carbonate* 

 with acetic acid and evaporating. 



Acetate of Potash, KO, C 4 H f O,, is a deliquescent salt crystallising 

 with difficulty ; it is used medicinally as a diuretic. It combines with 

 another equivalent of acetic acid, forming a binacetate, K<>, C 4 H,O, + 

 HO, C 4 H ) O 1 , which crystallises readily, and when distilled is decom- 

 posed into the neutral acetate and monobydrated acetic acid. 



Acetate of Soda, NaO,(' 4 H,()., + t!A<j., crystallises in oblique rhoml<ic 

 prisms. It is formed on a large scale in the prcjiaratinn of acetic acid 

 from cnide wood vinegar. The latter is neutralised with chalk, funn- 

 ing acetate of lime, which tn-ing mixed with sulphate of nod.i is divoiu- 

 posed into acetate of soda, sulphate of lime being simultai. 

 formed. 



Aeftute of Ammonia (Spirit of Mindereruf), NH 4 0, C.H.Oj, cannot 

 be well crystallised from its solution formed by neutralising the 

 carbonate of ammonia with acetic acid, since on evaporation ammonia 

 U expelled, and the solution becomes acid. It may be formed h 

 by distilling equal parts of acetate of lime and sal-ammoniac, when 

 binacetate of ammonia is given off as an oily fluid, which crystalline 

 in needles. Dry ammonia converts it into the neutral salt. Acetate 

 of ammonia has a cooling sweet taste and is a diaphoretic. Ac< t 

 lime, < '.it>< ',11 ,0 ,. crystallises in needles which ore efflorescent. 



Acetate of Alumina is used largely as a mordant in dveing. For 

 this purpose it is made by decomposing a solution of alum with acetate 

 of lime, in which case however the sulphate of potash, or ammonia of 

 the alum, remains dissolved ; the pure salt may be formed by substi- 

 tuting sulphate of alumina for alum, and acetate of lead for acetate 

 of lime. According to ('rum the formula of acetate of alumina is 

 AljOj, 2C 4 H,Oj + HOC t H,O 3 . Some of the metallic acetates are of 

 great importance in the arts. 



The Proto-acetate (FeOC,H s Oj), and the Setqui-acctale (Fe,0,, 

 3C 4 HjOj), of Iron, are both used as mordants by the calico printer. 

 They are both made on a large scale by dissolving iron hoops, nails, 

 or turnings, in crude pyroligneous acid. For the formation of proto- 

 salt, access of air is prevented ; for the sesqui-salt, encouraged. In 

 Boucherie'g process for preserving timber, the wood is impregnated 

 with acetate of iron. 



Neutral Acetate of Lead (Sugar of Lead, Salt of Saturn), PbO, 

 C,H,O ,, 3 Aq. , is prepared by dissolving litharge in excess of acetic acid ; 

 on evaporation, a mass of small white crystals is formed, resembling loaf 

 sugar, hut by careful management large transparent prismatic crystals 

 of the salt may be obtained. It is very soluble in water and alcohol, 

 and has a remarkably sweet taste. 



Tribanc Acetate of Lend (dunlanFt Water), 3 PbO, C,H,0 V SAq.. i.- 

 prepared by digesting seven parts of litharge with six parts of the 

 neutral acetate of lead in thirty parts of water. It crystallises in 

 minute needles. There are two other basic acetates of lead, the suh- 

 sesqui-acetate, 8PbO,2C 4 H.,O r Aq.,and the hex-acetate, 6PbO, C.H,O V 

 Aq., neither of which are of importance. All the subaoetates i 

 are decomposed by carbonic acid, and have a strongly alkaline reaction. 

 They arc employed in the refining of sugar. The neutral acet 

 copper, verditer, CuO, C.H,O, + Aq., is formed by dissolving verdigris 

 in hot :iceths acid : on cooling, beautiful dark green crystals are formed. 

 United with arsenite of copper, it forms Schweinfurth green, a beautiful 

 green pigment. 



The Diacetate of Cupper ( Verdiyrit), 2CuO, C 4 H,O, + <; > 

 (xired commercially, by exposing sheets of copper to the act: 

 acetic acid, produced from the fermenting marc of grapes. The 

 copjH-r liecomes encrusted with the crystalline salt, which is removed 

 and pressed into cakes. Pieces of cloth moistened with acetic a. 

 sometimes substituted for the grape marc. 



Verdigris is decomiMmed by water into a soluble subsesqui-acetato, 

 3CuO, 2C,H,0, + 6Aq., and an insoluble triKisic acetate, 8 

 C.H.,0, + Aq. 



There are many other metallic acetates, few of which however arc of 

 much importance. They are most of them characterised by their ready 

 solubility in water, and by yielding, on destructive distillation with 

 lime, a volatile inflammable liquid called Arctonc, q. v. He,te.| with 

 hydrate of potash or soda, they yield hydride of methyl (light 

 carbtirettod hydrogen). 



Acetic acid form* soluble salts with many of the organic bases, some 

 of which arc of great importance in medicine. 



