ETHYL, MKTHTL, ETC.] 



CHEMISTRY. 



415 



notice, some years ago, a lad, 12 years of age, part of 

 whose finger had to be amputated, wag placed under the 

 influence of the agent. To all appearance he was per- 

 fectly insensible to pain ; he was yet able to describe each 

 step of the operation, which he did as eacli was finished, 

 with an amazing exactness. On being restored (if we may 

 so say) to consciousness, he was perfectly unaware that 

 the top joint had been removed, and would not believe 

 the fact until he saw his finger, on the next day, when it 

 was uncovered for the purpose of dressing it. In several 

 case.<<, the administration of chloroform has been attended 

 with fatal consequences, in which, however, its action 

 could scarcely be properly assumed as the sole cause of 

 death. 



It may be as well for us to give a general glance over 

 the subject to which attention has been drawn in this 

 chapter, before proceeding further, inasmuch as it will, 

 to a large extent, form a basis on which we shall hereafter 

 have to build. Starch, sugar, and their products, were 

 the subjects on which we were to treat. We have found 

 that, from these vegetable products, a vast variety of sub- 

 stances, having no physical similarity to them, can be 

 obtained. Alcohol, ethers, acids, each having their own 



peculiarity of constitution, are readily producible from 

 the well-known articles of our daily food. Even a cursory 

 glance over the different substances we have mentioned, 

 or referred to, will be sufficient to lead every thoughtful 

 mind to reflect on the astonishing multiplicity of com- 

 pounds which may arise from the combination of three 

 elements, in variable proportions. We have, hitherto, 

 noticed that, from sugar alone, deadly poisons, favourite 

 beverages of all classes, medicines, condiments, and inter- 

 esting philosophical results, are easily obtained. Won- 

 derful as may be such discoveries, they are but an index 

 to the innumerable instances of a similar kind which 

 organic chemistry presents to our view. Perhaps, in no 

 branch of scientific inquiry can we find an instance in 

 which so few agents are, by the fiat of the Creator, em- 

 ployed in so great a variety of ways and purposes. This 

 fact has rendered the study of this portion of our subject 

 a matter of the deepest interest to most living chemists. 

 But, to the sagacity and researches of Liebig every 

 civilised nation is indebted, in a commercial and social 

 point of view ; his labours, chiefly, have opened out a 

 valuable and extensive field of inquiry, and have made 

 popular a subject of great difficulty. 



CHAPTER VIII. 

 METHYL, AMYL, ETC., AND THEIR PRODUCTS. 



Izr the last chapter, we remarked, that the substance 

 called ethyl, had the peculiar property of acting as a 

 base, and of forming certain definite compounds with 

 oxygen, chlorine, <bc., and acids. We now shall show 

 that other substances exist, having analogous properties, 

 equally capable of acting as bases, and of producing com- 

 pounds having very similar constitution to those pro- 

 duced by ethyl. 



The base of the first of the series is called Methyl 

 symbol, Me and it is composed of C a H 3 . It is con- 

 tained in ordinary wood-spirit, which is a hydrated oxide 

 of methyl The latter is obtained by the distillation of 

 wood The acid liquor produced is neutralised by lime, 

 and the spirit is produced therefrom. The product is a 

 limpid liquid, having an unpleasant smell ; it readily 

 burns on being inflamed ; and is largely employed for a 

 variety of purposes in the arts ; by cabinet-makers, as a 

 solvent for varnishes ; and to burn in lamps. Its specific 

 gravity varies with its purity, but should be about 0700 

 (water 1-000). 



Oxide of methyl is the analogue of ether, and may be 

 produced by distilling wood-spirit, just described, with 

 sulphuric acid. The chloride, iodide, bromide, sulphide, 

 and cyanide of methyl, are similar in constitution to the 

 compounds of the different substances with ethyl, and 

 have the same formula, excepting that that of methyl is 

 substituted. Similar observations apply to the com- 

 bination of sulphuric and other acids with methyl. 



During the slow combustion of wood-spirit a peculiar 

 acid is produced, which has also been obtained from the 

 well-known insect, the ant. It has, therefore, been 

 called formic acid. Combined with one equivalent of 

 water, its constitution is C 2 HO 8 HO. Formic acid 

 readily unites with bases forming the salts called formates. 

 It has a pungent smell, and readily blisters the skin if 

 applied to it. 



AMYL has a composition analogous to the substance we 

 have already described ; for, like ethyl and methyl, it 

 contains carbon and hydrogen only. Its general symbol 

 is Ayl, and it consists of C, H, t . Common fused oil 

 is a hydrate of its oxide. This liquid was long treated 

 as a waste product in distilleries. It is readily produced 

 in the distillation of spirit from potatoes ; has a strong 

 smell, and is combustible. 



Amyl forms a similar series of compounds to ethyl ; 

 hence we have its oxide, or amyl-ether, the chloride, 

 bromide, iodide, itc. 



Benzoyl symboUBz is, to some extent, analogous in 

 iU basic properties to ethyl, &c. Bitter-almond oil, 



which is a combination of benzoyl (C )4 H g 0,,) with 

 hydrogen, is a substance well known as an article in 

 general use for the purpose of perfumery, <bc. ; and is 

 a product of the distillation of water in which bitter- 

 almonds have been steeped. This substance, which is a 

 hydrate of benzoyl, becomes converted into benzoic acid 

 by oxidation. 



Benzoic acid is chiefly obtained, for ordinary use, by 

 the sublimation of gum-benzoin. When the latter sub- 

 stance is heated, the acid rises in vapour, and condenses 

 in fine crystals. During its volatilisation, the acid has a 

 very powerful smell ; it is hence used as an ingredient in 

 pastiles, incense, dec. "It readily forms salts with bases, 

 called benzoates. 



Benzoyl forms numerous compounds besides those we 

 have mentioned, but they are not generally of interest. 

 The constitution of some of them is given below, in 

 tabular order, with which we shall content ourselves, 

 without entering into any further description of them: 



Chloride of benzoyl . . Bz Cl 

 Iodide ,, ,, . . . Bz I 



Sulphide ,, ,, . . Bz S 



A peculiar acid, having some connection with the ben- 

 zoyl series, may here be named. It is found in the urine 

 of domestic animals, and is termed hippuric acid. It is 

 scarcely soluble in water ; is decomposed into benzoic 

 acid, (Sec., by heat, and forms salts with alkalies. This 

 acid contains a portion of nitrogen as a constituent. 



We shall include with the series two other bases, 

 analogous to those we have described namely, kakodyl 

 and salicyl ; although the latter appears to have some 

 analogy to the vegetable alkalies, which we shall have to 

 speak of presently. 



K;ikodyl symbol Kd is a peculiarly offensive, and 

 fearfully poisonous compound, composed of C^ H, As, 

 thus including an equivalent of a metal, arsenic, in its 

 composition. Its oxide is obtained by distillation, from 

 a mixture of acetate of potass and arsunious acid ; the 

 product is to be condensed in a cold vessel, when a dense 

 liquid will be obtained, which is the impure oxide. To 

 obtain it in a pure state it must be re-distilled with 

 potass, iu a retort, filled with hydrogen. This operation 

 is of the most dangerous character, from the poisonous 

 nature of the substance produced. 



Like ethyl, <tc., kakodyl produces a chloride, iodide, 

 d-c. It js also susceptible of oxidation, producing the 

 kakodylic acid, having a constitution of C 4 H, O,. 



The whole of the combinations of kakodyl are curious, 



