The Art of Perfumery, and Methods of Obtaining the Odors of Plants Part 35

To obtain the xanthine we treat the petals of yellow flowering dahlias with alcohol, which quickly dissolves the yellow coloring matter, besides the fat and resin. The solution is evaporated to dryness, and the residue treated with water, whereby the fat and resin are separated.

The water is again evaporated to dryness, and the residue treated with absolute alcohol. The resulting solution diluted with water is mixed with neutral acetate of lead, which precipitates the coloring matters.

The lead precipitate is then decomposed with sulphuric acid, upon which the xantheine which remains dissolved in the water is purified by alcohol.

Xantheine is soluble in water, alcohol, and ether, but crystallizes from none of these solutions. Alkalies color it intensely brown. Its power of coloration is considerable. It dyes various fabrics of a yellow tone, which is without brilliancy. Acids again destroy the brown coloration produced by alkalies. Xantheine combines with most metallic bases, and forms therewith yellow or brown insoluble lakes.

The facts here related agree with all which has been previously observed regarding the coloring matters of flowers. It is known that blue flowers can become red, and even white, where their coloring matter is destroyed, but never yellow--and _vice versa_. These three coloring matters can generate the colors either alone or by admixture, which are seen in flowers; but whether they are the only matters which color flowers, we are at present unable to determine.--_Journal de Pharmacie._

IMPROVED PROCESS FOR BLEACHING BEES'-WAX AND THE FATTY ACIDS.

BY MR. G.F. WILSON.

This improved process consists of two parts:--1st, the application of highly-heated steam to heat the fatty matters under treatment, by which means the requisite heat for melting these substances is obtained, and at the same time the atmosphere is thereby excluded; the heated steam so applied in its pa.s.sage off, carries with it the offensive smells given off by the fatty matters, and being made to traverse a pipe or pa.s.sage up or along which gaseous chlorine is allowed to flow, a complete disinfection of the offensive products is thereby effected. 2dly, the treating of bees'-wax in a mixture of hard acid fat and bees'-wax, with compounds of chlorine and oxygen, preferring to employ that disengaged from chlorate of potash by treating it with sulphuric acid. For this purpose, Mr. Wilson takes at the rate, say, of a ton of yellow bees'-wax, and melts and boils it up with free steam for about half an hour. It is then allowed to stand a short time, and is then decanted into another vessel provided with a steam-pipe to emit free steam; about 20 lbs. of chlorate of potash is added, and the steam turned on; 80 lbs.

of sulphuric acid, diluted with a like weight of water, is then gradually added. The matters are allowed to stand for a short time, and are then decanted into another vessel, and again boiled up with free steam, and treated with a like quant.i.ty of diluted sulphuric acid. The bees'-wax is then decanted into a receiver, and is ready for use. The bees'-wax may, before undergoing these processes, be combined and boiled up with a hard fatty acid, and then treated as above described.

CHEMICAL EXAMINATION OF NAPLES SOAP.

A. Faiszt has submitted this celebrated shaving soap to a.n.a.lysis. He states that it is made by saponifying mutton fat with lime, and then separating the fatty acids from the soap thus formed, by means of a mineral acid. These fatty acids are afterwards combined with ordinary caustic potash to produce the Naples soap. He found that 100 parts of this soap contained

Parts.

Fatty acids, 57.14 Potash combined with the fatty acids, 10.39 Sulphate of potash, chloride of pota.s.sium, with a trace of carbonate of potash, 4.22 Silica, &c., 0.46 Water, 27.68 ----- 99.89 _Gewerbeblatt aus Wurttemberg._

MANUFACTURE OF SOAP.

The removal of the duty from soap, and the consequent emanc.i.p.ation of this branch of industry from the tender mercies of the Excise, has given a fresh impetus to the manufacture of this important article of daily use, and enabled some processes to be practically carried out in England, which, previous to the removal of the duty, could not be adopted in this part of her Majesty's dominions.

It will doubtless appear strange to those unacquainted with the circ.u.mstances, that owing to the mode of levying the duty by admeasurement, and not by actual weight, the maker of a particular kind of soap was debarred the privilege of manufacturing in this country.

Fortunately for him, the manufacture of soap being free from all Excise restrictions in Ireland, he was enabled to carry out his process in the sister kingdom, whence it was exported to England, and admitted here on payment of the Customs' duty, which was the same as the Excise duty on its manufacture here. All this roundabout method of doing business is now done away with, and no restriction now exists to mar the peace of the soap manufacturer.

Amongst various new processes lately introduced is that of Mr. H.C.

Jennings, which is practically carried out in the following manner:--

Combine 1000 lbs. of stearic or margaric acid, as free from elaine or oleine as possible, or palmatine, or any vegetable or animal stearine or margarine, at the temperature of 212 Fahr., with a solution of bicarbonate of potash or soda, specific gravity 1500. Constantly stir or mix until an intimate combination is obtained, and that the elements will not part when tried upon gla.s.s or any other similar substance. When the ma.s.s is cooled down to about 60 Fahr. add one pound per cent. of liquor ammoniae, specific gravity 880, and one pound per cent. of strongest solution of caustic potash; these are to be added gradually, and fully mixed or stirred until perfectly combined. Dissolve 15 to 18 pounds per cent. of common resin of commerce, by boiling it with a solution of subcarbonate of potash and common soda of commerce, in equal parts, as much as will give the solution a specific gravity of about 1800, when boiling hot. Mix these perfectly with the above-mentioned stearic or margaric acids, and carbonated alkali; then add a strong solution of caustic potash or soda, until a perfect saponification is produced. The dose of caustic alkali will much depend upon the purity of the stearine or margarine employed. The separation is now effected by using common salt, or sulphate of soda, &c., as is known and practised by soap manufacturers. If the soap intended to be produced is to be colorless, no resin must be employed, and a larger dose of liquor ammoniae and caustic alkali must be used, according to the dryness of the stearine matters to be operated upon.

A SIMPLE AND CERTAIN METHOD TO DETERMINE THE COMMERCIAL VALUE OF SOAP.

BY DR. ALEXANDER MuLLER.

In consequence of the ceremonious process by which the fatty acids are determined in one portion of the soap, and the alkali by the incineration of another, I consider the following method is not unworthy of publication, because it appears to afford quicker and more correct results by reason of the greater simplicity of the manipulation. It is available princ.i.p.ally for soda soaps, which are the most common; but it may be also employed with corresponding alterations for soaps which have other bases.

A piece of soap weighing two or three grammes is dissolved in a tared beaker gla.s.s of about 160 cubic centimetres capacity with 80 to 100 cubic centimetres of water, by heat, in a water-bath, and then three or four times the quant.i.ty of diluted sulphuric acid or as much as is necessary to decompose the soap, added from a burette. When, after repeated agitation, the fatty acids have separated in a transparent clear stratum from the aqueous solution, it is allowed to cool, and then the contents of the beaker gla.s.s are placed in a moistened filter, which has been previously dried at 212 Fahr. and weighed. The contents of the filter are washed until their acid reaction disappears. In the meanwhile the beaker gla.s.s is placed in a steam-bath, so that, it being already dry, may support the washed and partly dry filter, which is laid on the mouth of the gla.s.s as if it were in the funnel. The fatty acids soon pa.s.s through the paper, and for the most part flow ultimately to the bottom of the beaker gla.s.s; the increase of weight of which, after cooling, and the subtraction of the weight of the filter, gives the quant.i.ty of fatty acids present in the soap. A second drying and weighing is not necessary, if on the cold sides of the interior of the gla.s.s no damp is to be observed, which is occasioned by a trace of water still present. If the quant.i.ty of oxide of iron added to marble the soap is considerable, it may be easily found by incinerating the filter and determining the weight of the residue.

The fluid runs from the fatty acids on the filter, which, with the was.h.i.+ngs, has been preserved in a sufficiently large beaker gla.s.s, is colored with tincture of litmus, and decomposed with a test alkaline solution until the blue color appears. The difference of the quant.i.ty of alkali required to neutralize the sulphuric acid, and the quant.i.ty of sulphuric acid used in the first instance, allows a calculation to be made as to the quant.i.ty of effective alkali in the soap, for example:--

23.86 grms. of soap (partly cocoa-nut oil soap).

17.95 " fatty acids with filter.

04.44 " filter.

----- 13.51 grms. of hydrates of fatty acids = 56.62 per cent.

28.00 cub. cent. of the diluted sulphuric acid applied for the decomposition of the soap, of which 100 cub. cent.

represent 2982 grms. of carbonate of soda.

17.55 cub. cent. of alkaline fluid, which were used for the saturation of the above acid, and of which 100 cub.

cent. saturate an equal quant.i.ty of that acid.

---- 10.45 cub. cent. of the sulphuric necessary for the alkali contained in the soap, representing 0.1823 grms. of soda = 7.64 per cent.

A determination of the alkali as a sulphate afforded in another portion of soap 9.57 per cent. of soda, because the sulphate of soda and chloride of sodium present in the soap gave up their alkali.

The alkaline fluid applied by me was a saccharine solution of lime, which can be naturally replaced by a solution of soda, and must be if the chloride of sodium and sulphate of soda mixed with the soap shall be determined in the following way:--

The fluid again exactly neutralized with alkali is evaporated to dryness, and the residue gently heated to redness. As in the above manipulation, the fluid was not heated to the boiling point, the original chloride of sodium and sulphate of soda are contained in the weighed residue, besides the soda of the soap and that which has been added with the sulphuric acid, forming sulphate of soda. A second exposure to a red heat with sulphuric acid converts the whole residue into sulphate of soda, and from the increase of weight, by a comparison of the equivalents of NaCl and NaO, SO_{3} the quant.i.ty of the former may be decided. According to the equivalents which Kopp furnished in 1850, the increase of weight to the chloride of sodium is as 1:4.68. The original sulphate of soda must be, lastly, found by the subtraction of the same salt formed plus the calculated chloride of sodium from the first heated residue.

In practice, it is seldom necessary to proceed with the determination of the chloride of sodium and sulphate of soda, except with stirred and cocoa-nut oil soaps; certainly less of the truth is seen if, after the above determination of the fatty acids and the effective alkali, the absent per centage of water is introduced in the calculation, than if the water is reckoned, which is never completely evolved from soap, even technically prepared at 302 Fahr., and another determination made of the fatty acids or alkali _en bloc_ the fatty acids, or even the alkaline contents.

The method here given partakes of the usual imperfections, that the fatty acids as well as the unsaponified soap are equally estimated, and the mixed hydrate or carbonate of the alkali as well as the combined alkali. The presence of the carbonate can be easily recognized by the foaming of the soap solution, upon the addition of the sulphuric acid.

These imperfections, however, are of little importance.

It must be granted that the minutely correct determination of the const.i.tution of soap must be always yielded up to those who are technically conversant with this department of chemistry, the estimation of free alkali and unchanged fat excluded in, at least, by certain ages of the soap. Further, a considerable excess of one or another ingredient soon betrays itself by a corresponding departure in the soap of the characteristic properties of a good product, and a small excess can be judged sufficiently exact from the proportion of the alkali, which, supposing soda present, should not amount to more than 13 per cent. with a pure cocoa-nut oil soap, not less than 11.5 per cent. with a tallow soap; but with palm oil and mixed soaps the one or the other limit approximates.--_Journal fur Praktische Chemie._

ON THE NATURAL FATS.

BY DR. CHARLES LoWIG.

The fats which exist in nature can be divided into the general and the special; the former exist in almost all plants and parts of plants; the latter includes only some vegetable substances, as _laurostearine_, _myristicine_, and _palmatine_. The consistence of fats of the general kind depend upon the proportions of margarine, stearine, and oleine contained in them. The former preponderate in the solid fats (b.u.t.ter, lard, and tallow); and the latter in the fluid ones or oils. According as an oil contains oleic acid or olinic acid, it is termed a fatty or drying oil. To the cla.s.s of fatty oils belong olive, almond, hazel-nut, beech, rape oils, &c.; to that of drying oils, linseed, nut, hemp, poppy, grape-seed, oils, &c.; which are used for varnishes.

In the vegetable kingdom the fats are chiefly in the seeds and in their coverings, seldom in the perispemium (poppy), and in the fleshy substance surrounding the seed (olive). The fat in the seed is mostly enclosed in cells with a proteine compound. In the animal kingdom certain parts of the body are quite filled with fat-cells, particularly under the skin (_Paniculus adiposus_), in the cavities of the abdomen, in the so-called _omentum_, in the kidneys and the tubulated ca.n.a.ls of the bones. Fat is also enclosed in cells (fatty globules) in milk.

It is established, without a doubt, that a greater portion of the fat which exists in the animal kingdom originates from the vegetable kingdom, for it is introduced into the body cotemporaneously with the proteine compounds of that kingdom. A portion of the fat as well as wax is formed in the animal organismus, as shown by a number of observations, and in most cases it is unquestionable that the non-nitrogenous nutriments, as starch, serve for the formation of fat by a process of deoxidation; nevertheless, the formation of fat in the animal body appears only to take place when the substances containing starch enter the body simultaneously with fat.

If the fat existing in the animal body is contained in cellular tissue, its separation may be simply effected by placing the incised tissue in hot water. The cells burst and the fat collects itself on the surface of the water. If vegetable substances contain fat in large quant.i.ty, as, for example, seeds, it may be obtained by expression. The dried seeds are bruised and expressed between either cold or hot metallic plates.

Olives are laid in heaps before expression; when they begin to ferment, they can be completely expressed. If animal and vegetable substances contain only a little fat, it must be extracted by ether.

In the pure condition the fats are mostly odorless and tasteless; when they possess an odor, it arises mostly from the presence of small quant.i.ties of volatile fatty acids, as butyric acid, capric acid, &c.; which becomes free through the decomposition of their oxide of glycyl combinations. This ensues by the presence of water and air through a kind of fermentation, and as it appears, by the presence of a nitrogenous substance. The fats are insoluble in water, and, with the exception of castor oil, are taken up by cold alcohol in very small quant.i.ties, however, more in proportion as they contain oleine. In boiling alcohol they are dissolved, but are, for the most part, again separated on cooling, particularly those rich in stearine. All fats are taken up by ether but those containing stearine in the smallest quant.i.ty.

Their specific gravities fluctuate between .91 and .93. When heated, fats a.s.sume a dark color, and boil between 482 and 572 Fahr., but the boiling-point continuously rises, while an uninterrupted decomposition proceeds. From oxide of glycyl ensues acroline; oleic acid affords a fatty acid, and among the decomposition products of fats containing stearine and margarine are found pure margaric acid, and, at the same time, some hydro-carbons are formed. When exposed quickly to a high temperature, fats are completely decomposed. (Oil gas.) In closed vessels the pure fats undergo no change, but, placed in thin layers in the air, the fats containing oleine and oline rapidly absorb oxygen under the strong evolution of heat, which will inflame porous bodies, as cotton wool. The purer the fats are the more quickly their oxidation results. When the fats contain slimy materials, these latter can be destroyed with a little oxide of lead and water. (Preparation for the application of varnishes.) The action of nitric acid, nitrous acid, chlorine, sulphuric acid, &c., on fats is the same as that of these bodies on the fatty acids. The fatty oils dissolve sulphur in the heat which is again partly precipitated on cooling. When sulphur is heated with fatty oils, namely, with linseed oil, it dissolves by degrees, and a thick dark ma.s.s is formed, the so-called balsam of sulphur. By raising the heat, a violent reaction ensues under the evolution of sulphuretted hydrogen, and, at the same time, an oil resembling oil of garlic volatilizes. This oil begins to boil at 160 Fahr., but its boiling-point rises continually.