12 



MODE OF MANUFACTURING ARTIFICIAL ESSENCES. 



[1853 



of dry acetate of potash, with 1 to l-.V parts of sulphuric acid. 

 The liquid having been kept for some time at a gentle heat, the 

 acetate of oxyde of amyle is separated by adding water, and pro- 

 ceeding as above explained. 15 parts of acetate of oxyde of 

 amyle are mixed with l£ pari of vinegar ether (vinegar napthn, 

 acetate of oxyde of et/hyle,) and dissolved in 100 to 120 parts of 

 spirits of wine, as in the case of pmn apple extract; an acid, for 

 instance, tartaric or citric, should be added to the sugar solution, 

 on making use of the pear extract, which addition makes the fla- 

 vour of the bergamot pear better distinguishable, and the taste 

 acquires at the same time more of the refreshing qualities of fruit. 



Apple Oil. — What is called apple oil, is a solution of valeri- 

 anate of oxyde of amyle in spirits of wine, which may be obtained 

 as a secondary product when fusel oil is distilled with chromate 

 of potash and sulphuric acid for the preparation of valerianic acid. 

 The light solution which collects in the tops of the distilled liquid 

 contains valerianate of oxyde of amyle, together with other 

 liquids, such as adehyde, which gives to the product a less agree- 

 able taste and smell. It is therefore to be preferred for preparing 

 pure valerianate of oxyde of amyle. 



For preparing valerianic acid, 1 part of fusel oil is mixed by 

 6 nail portions with 3 parts of sulphuric acid, and afterwards 2 

 parts of water are added. At the same time, a solution of 24; 

 parts of bichromate of potash in 4-^ parts of water, is heated in 

 a tubular retort; the first liquid is then permitted to flow very 

 slowly into the liquid of the retort in such manner that the boil- 

 ing continues but very slowly. The liquid which is distilled over 

 is saturated with carbonate of soda, and is evaporated either to 

 dryness for obtaining valerianate of soda., or to the consistency of 

 syrup, when sulphuric acid is added, (say 2 parts of concentrated 

 acid diluted with the same quantity of water, for every three 

 parts of crystalline carbonate of soda.) The valerianic acid forms 

 an oily layer on the upper part of the liquid : which latter will 

 still yield some valerianic acid, on being submitted to distillation. 

 For preparing valerianate of oxvde of amyle, 1 part by weight of 

 pure fusel oil is mixed carefully with an equal quantity by weight of 

 common English sulphuric acid ; the resulting solution is added 

 to 1^- parts of oily valerianic acid, or to 1^ parts of dry valerian- 

 ate of soda, and is treated by a water bath, and then mixed with 

 water, by which means the impure valerianate of the oxyde of 

 .amyle will be separated ; this is washed several times with water, 

 afterwards with a solution of carbonate of soda, and finally again 

 with water. In preparing this compound, it is essential that the 

 mixture of sulphuric acid and fusel oil, with valerianic acid, 

 should not be heated to a too high degree, or too long, as the 

 product would thereby acquire an insufferably pungent smell 

 when required for use. 1 part of valerianate of oxyde of amyle 

 js dissolved in 6 or 8 parts of spirits of wine, and acid is added 

 in the same manner, as has been before explained in the prepara- 

 tion of other extracts. 



Artificial Oil of Bitter Almonds. — When Mitscherlich, in 

 1834, discovered nitro-benzole, he little thought, after twenty 

 years to find this body in an industrial e thibition. He certainly, 

 at that time, pointed out the remarkable resemblance which tlie 

 odor of nitro-benzole had to that of bitter almonds; but the only 

 sources for obtaining benzole at that time, viz., the oil of com- 

 pressed gas, and the distillation of benzoic acid, were much too 

 expensive, and put an end to the idea of substituting the use of 

 nitro-benzole for oil of bitter almonds. Mansfield, however, in 

 1849, showed by careful investigation, that benzole may be pro- 

 duced easily and in large quantities from oil of coal tar,' and this 

 discovery has not been lost sight of in the arts. Amono- the arti- 

 cles of French perfumery in the Great Exhibition, with the title 

 of artificial oil of bitter almonds, and the fanciful name of essence 



of Mirbane, there were several specimens of oils, which consisted 

 of more or less pure nitro-benzole. The apparatus used in the 

 preparation of this substance is that proposed by Mr. Mansfield. 

 It consists of a large glass worm, the upper end of which branches 

 into two tubes, which are provided with funnels. A stream of 

 concentrated nitric acid flows slowly through one of these funnels, 

 whilst the other is for the benzole, (which for this purpose need 

 not be absolutely pure.) At the point at which the tubes of the 

 funnels are united, the two bodies come in contact, the chemical 

 compound formed becomes sufficiently cooled in passing through 

 the worm, and only requires to be washed with water, and finally 

 with some weak solution of carborate of soda, to be. ready for 

 use. Although the nitro-benzole closely resembles oil of bitter 

 almonds, in physical properties, it possesses, however, a somewhat 

 different odor, readily recognized by a practised person. How- 

 ever, it answers well for scenting soap, and would be extensively 

 applicable for confectionary and for other culinary purposes. For 

 the latter purpose it has the special advantage over oil of bitter 

 almonds, that it contains no prussic acid. 



The application of organic chemistry to perfumery is still in its 

 infancy ; and we may expect that a careful survey of those etheis 

 and etherial compounds with which we are at present acquainted 

 will lead to further results. The interesting caprylic etheis which 

 M. Blouis has lately discovered are remarkable for their extreme- 

 ly aromatic odor, (thus the acetate of caprylic oxide possesses an 

 odor as strong as it is agreeable,) and promises, if they can be 

 obtained in larger quantities, to yield materials for perfumery. — 

 Hoffmanns letter to Liebig. 



The subject of the composition and artificial production of the 

 various extracts of fruit and other similar perfumes and essences, 

 strikingly illustrates the wonderful progress which has been made 

 in organic chemistry within the last few years. A position has 

 been taken by some chemists who have carefully investigated this 

 subject, which cannot at present be controverted, that the extracts 

 or perfumes of the various fruits which can be artificially prepared 

 in our laboratories from the basic organic radicals, are identical 

 and (he same with those which nature carefully elaborates in the 

 apple, the pear, the pine apple, banana, and the like. The whole 

 subject has been investigated more carefully, and has been 

 applied to more practical purposes than the public is generally 

 aware of. Take for instance the well-known perfumes known as 

 " Lublin's Extracts," extract of geranium, millefleurs, new-mown 

 hay, and many others ; all of these are said to be prepared from 

 two or three of the common and cheap essential oils, and from 

 the organic radicals. In addition to perfumes the most agreeable, 

 odors of the most disgusting and nauseous character can also be 

 produced by like means; as for instance, the odor of the bed-bug, 

 squash-bug, and of many of the common weeds and plants. As 

 an odor or perfume of a different character can be produced by 

 the action of each different acid on the different oxydes of the 

 organic radicals, the number of bodies of this character capable 

 of being produced is almost innumerable, and may possibly em- 

 brace every known odor or perfume which is now recognized in 

 the animal, vegetable or mineral kingdom. 



The various artificial extracts of fruit have been applied to the 

 flavouring of an agreeable species of confectionary known as the 

 ■" acidulated fruit drops." These have been denounced as poison- 

 ous by some persons, on the ground that fusel oil is known to pro- 

 duce deleterious effects ; and as a natural consequence the confec- 

 tionary referred to has been discarded. There is, however, no 

 foundation for such statements or belief, and if the confectionary 

 flavoured with these extracts has in any case produced injurious 

 effects, it is undoubtedly to be referred to an injudicious consump- 

 tion of it, and not to any inherent deleterious property. — Ameri- 

 can Annual of Scientific Discovery. 



