1853] 



MODE OF MANUFACTURING ARTIFICIAL ESSENCES. 



11 



Exhibition, th.3 artificial extracts of fruits were particularly 

 deserving of attention. Although same of these extracts, as for 

 instance, butyric ether, have already found applications, their use 

 has been hitherto only on a very limited scale. It is now, Low- 

 ever, no longer to be doubted but that the majority of our arti- 

 ficial organic compositions will, era long, be extensively applied, 

 and their practical applications cannot but have a very stimulating 

 effect on the study of organic chemistry, which will again most 

 probably lead to the discovery of technical applications for the 

 new organic compositions, which the investigations of our mo- 

 dern chemists have furnished us with. Among the extracts of 

 fruit exhibited by a London manufacturer, those which more 

 particularly attracted attention were pine apple oil, bergamot pear 

 oil, apple oil, grape oil, cognac oil, (fee. Several of these oils 

 have been analyzed by M. Faiszt, of Stuttgardt. We give here 

 a succinct description of some of these extracts, and of their ma- 

 nufacture. 



Pine Apple Oil. — This product consists of a so'ution of 1 

 part of butyric acid ether, in 8 to 10 parts of spirits of wine. 

 For preparing butyric acid ether, pure butyric acid is required, 

 and this is obtained most readily and in greatest quantity, by the 

 fermentation of sugar, or of St. John's bread, (siliqua dulcis.) 

 For preparing butyric acid from sugar, M. Bentch takes a solu- 

 tion of 6 pounds of sugar, and half an ounce of tartaric acid in 

 26 pounds of water, which is left to stand for some days; at the 

 same time about a quarter of a pound of old decayed cheese is dif- 

 fused in 8 pounds of sour mi k, from which the cream has been 

 removed; and after this has also stood for some days, it is tnixed 

 with the first solution, and the whole is kept from four to six 

 weeks at a temperature of about 24 = to 28 " Reaumer, water 

 being added from time to time to replace that which is lost by 

 evaporation. After the evolution of gas has entirely ceased, the 

 liquid is dissolved with its own bulk of water, and finally 8 pounds 

 of crystalized soda, dissolved in 12 pounds to 16 pounds of wa- 

 ter are added to it. The liquid is then filtered and evaporated 

 till it weighs only 10 pounds, when a quantity of 5^ pounds of 

 sulphuric acid, (nordhausen, or fuming sulphuric acid,) diluted 

 with 5i- pounds of water, is carefully mixed with it by small por- 

 tions at a time. The butyric acid, in the state of an oily sub- 

 tance, will now appear on the surface of the liquid, from which 

 it may be skimmed off; but as the remaining liquid still contains 

 some butyric acid, it is submit'ad to distillation, by which means 

 another portion of diluted butyric acid is obtained, which may be 

 be concentrated by means of melted chloride of calcium, or by 

 saturating it with carbonate of soda, evaporating and decom- 

 posing by sulphuric acid. By this method If pounds of pure 

 butyric acid are obtained from 6 pounds of sugar. 



M. Marsson says that the same product may be obtained from 

 St. John's bread (siliqua dulcis,) by taking 4 pounds of mashed 

 St. John's bread, and mixing it with 10 pounds of water and 1 

 pound of chalk ; the liquid matter must be maintained from three 

 to four weeks at a temperature of from 25 3 to 35 = Reaumer, 

 and be often and well stirred, and from time to tiire the water 

 that has evaporated must be replaced. After fermentation has 

 ceased, a quantity of water equal to the bulk of the liquid is added 

 and afterwards a concentrated solution of 2^ pounds or 2f 

 pounds of carbonate of soda, when it is finally evaporated. To 

 the concentrated liquid is then added 1^ pounds to 2 pounds of 

 sulphuric acid, diluted with 2 pounds of water; and the remain- 

 der of the process is performed as already deseri ed. By this 

 method a little more than half a pound of coloured butyric acid 

 will be obtained. The acid, however, retains a peculiar smell 

 from the St. John's bread, which continues even in the ether pre- 

 pared from the same, whereas that prepared from sugar gives an 

 ether of a very pure smell. It will be found advantageous to 



agitate the oily butyric acid with chloride of calcium, in order to 

 deprive it entirely of its moisture. 



For preparing butyric acid ether, (butyrate of oxyde of ethyle,) 

 from butyric acid, 1 pound of butyric acid is dissolved in 1 pound 

 of rectified alcohol, (95 c Tralles,) and is mixed with one-half to 

 one-fourth of an ounce of concentrated sulphuric acid; the com- 

 pound is heated for some minutes, when the butyric acid ether 

 will form a thin layer on the top. The whole is then mixed 

 with half of its bulk of water, and the upper layer taken off; the 

 remaining liquid being submitted to distillation, yields another 

 quantity of butyric acid ether, which is mixed with that obtained 

 in the first instance, and the whole well agitated with a very dilu- 

 ted solution of soda, in order to deprive it of all the acid; 

 which operation should be repeated several times if a very pure 

 ether is desired to be obtained. Care should be taken to use but 

 small quantities of the diluted soda solution at a time, so as not to 

 lose too much ether, this latter being in some measure soluble in 

 water. When large quantities are to be acted upon, the washino- 

 water (eau de lavage,) is collected, mixed with an equal volume 

 of spirits of wine, and distilled, by which means a solution of 

 pure butyric acid ether in spirits of wine is obtained. 



Butyric acid ether may be also obtained immediately from 

 butyrate of soda, by dissolving 1 part of this salt in 1 part of 

 rectified alcohol, adding 1 part of sulphuric acid, and heating 

 some minutes. The ether collects on the top of the liquid, and is 

 purified by washing with water and with diluted soda solution. 



For preparing pine apple oil, 1 pound of butyric acid ether is 

 dissolved in 8 pounds to 10 pounds of spirits of wine, which 

 should have been previously deprived of its empyreumatic or 

 fusel oil. Pure French spirits of wine will be found best suited 

 for this purpose. According to the purpose for which the pine 

 apple oil is to be applied, either rectified alcohol of 80 = to 90 ° 

 Tralles, or brandy of 40 ; to 50 ; , should be used for dissolving 

 the ether. 20 drops to 25 drops of such an extract will suffice 

 for giving a strong pine apple odour to 1 pound of sugar solu- 

 tion, to which some acid, such as tartaric or citric acid, is generally 

 added. 



Bergamot Pear Oil. — What is called pear oil is an alcoholic 

 solution of acetate of oxyde of amyle, and acetate of oxyde of 

 ethyle, prepared from potato fusel oil, (the hydrate of oxyde of 

 amyle.) The potato fusel oil, or oil of potato spirits (in German, 

 fuseloel,) is the compound distilled over towards the end of the 

 first distillation of spirits made from potatoes, and is an oily liquid 

 of a very strong and nauseous odor. This oil, in the state in 

 which it is obtained from large potato brandy distilleries, is never 

 pure; but it may be purified by agitating it with a diluted soda 

 solution, when the pure fusel oil collects as an oily layer on the 

 top of the liquid ; this oily substance is then submitted to distil- 

 lation, and that part which distils over at 100 = to 112" Reau- 

 mer, is collected, and forms the pure fusel oil. 



For preparing acetate of oxyde of amyle from this fusel oil, 1 

 pound of pure ice vinegar is mixed with an equal quantity of fusel 

 oil, to which is added half a pound of sulphuric acid; the liquid 

 is digested for some hours at about 100 = , when the acetate of 

 oxyde of amyle separates, particularly on being mixed with a 

 small quantity of water. The remaining liquid, when mixed 

 with more water, yields, on being submitted to distillation, a fur- 

 ther quantity of acetate of oxyde of amyle. The entire mass of 

 oxyde of amyle thus obtained is now agitated several times with 

 water and a little soda solution, in order to deprive it of all free 

 acid. 



The acetate of oxy.le of amyle may also be obtained by tak- 

 ing 1 part of fusel oil to 1 \ part of dry acetate of soda, or 2 parts 



