The absence of free fatty acids in edible oils and fats is a very important desideratum. Hence, in all refining processes, the complete removal of free fatty acids and of the objectionable products which seem to follow in the wake of the once formed free fatty acids, namely, those which impart to the oil the properties we comprise under the term "rancidity," is the chief aim of the manufacturing processes. Alkalis and alkaline earths are almost exclusively used for these purposes.

The physical method consists chiefly in filtering, with a view to brightening the oils by the removal of the adhering moisture and suspended matter of an albuminoid character, and, if colouring matter is to be eliminated at the same time, in treating with either charcoal or fuller's earth. The latter process is, of course, followed by filtration, in order to get rid of the charcoal or fuller's earth, which absorb and retain the colouring matters.

A further requisite of edible oils is that they should not congeal at temperatures near the freezing point. Most olive oils practically fulfil this demand. In the case of cotton seed oil, however, which is at present used in enormous quantities as an edible oil, or for adulterating high-class edible oils, a solid portion, termed "stearine," separates out at a temperature of about 50° F., as exemplified by the specimens before you.

In order to render cotton seed oil suitable for the table, this "stearine" is removed; as the technical term runs, the oil is "demargarinated."

Originally the process of "demargarination" was a natural process, and consisted in allowing the oil to stand in large vessels during the winter, when the "stearine" settled out as a solid mass at the bottom of the vessel, so that the supernatant clear oil could be drawn off. Hence, such "stearine-freed" or "demargarinated" oils are designated by the term: "winter oils."

This simple process has, however, become too expensive, owing to the large amount of capital locked up in the enormous quantities of cotton seed oil that had to be stored. Hence, more rapid processes have been introduced. These consist in artificially refrigerating the oil, and filtering off the "stearine" through filter-presses, or removing it by pressure in hydraulic presses. It need hardly be added that in the latter case the whole process must be carried out in artificially cooled

rooms.

Through the introduction of demargarinating

processes, oils which were objectionable as table oils on account of their separating 'stearine,” are being added to the range of edible oils. Such oils are arachis oil, and notably that class of Tunisian olive oils which hitherto could not be mixed with the finest Italian and French olive oils, owing to their being exceptionally rich in "stearine."

The industry of edible fats has received, during the last decade, a very great impetus; notwithstanding its rapid development, this industry is, however, in my opinion, still in its infancy. One of the most important edible fats, butter, claims to belong to the dairy industry. In the interest of the butter industry itself, manufacturing in large establishments should certainly be preferred to the nursing of a kind of home industry under conditions which are not always above suspicion as regards cleanliness. It is just this element which, in addition to the cheapening of food stuffs, has given the enormous impetus to the manufacture of margarine.

The prejudice against this product, which popular ignorance connected with a conglomerate of all kinds of oils and fats, even of fish and train oils and refuse fats, or as a Member of Parliament picturesquely termed it about fifteen years ago, "all the greasy rubbish of the world which is being dumped down in this country," is fast disappearing. If we look at the shop windows of our grocers, it may be said to have already disappeared. The enormous strides which this industry has made are the best possible proof that it has come to stay.

The first and foremost conditions of this industry are the utmost cleanliness and the employment of the purest and freshest materials, combined with the importance of imparting to the product an attractive and even appetising appearance.

From a sanitary point of view, not the slightest objection can be raised against the substitution of cheaper animal or vegetable fats for the expensive cow-butter, and it is rather desirable that this industry should extend, yielding, as it does, cheap palatable food stuffs and thereby tending to exclude from consumption unhealthy fat from diseased animals, prepared under conditions which do not satisfy the most rigorous demands as regards cleanliness.

The origin of the margarine industry dates back to the times of the Franco-German war, when the needs of the beleaguered population of Paris demanded the resumption of earlier

experiments of Mège-Mouriès, which had attracted, a few years before, the attention of the emperor Napoleon.

The fact that butter substitutes lend themselves to fraudulent purposes, as we can unfortunately see every day if we pay some attention to this subject, should be no barrier to the extension of the industry; it is rather the duty of the legislator to render such fraud impossible than to prevent the proper expansion of the margarine industry. Long before margarine made its appearance butter had been adulterated on an immense scale, and the introduction of margarine had a wholesome effect in staying the hands of the adulterator, as the formerly favourite adulterants, such as clay, chalk, gypsum, flour, potato pulp, ground white cheese, and similar substances which used to form the stock-in-trade of the adulterator, have disappeared from the list in order to make room for the harmless, but much less readily detectable, margarine.

Margarine consists chiefly of a mixture of animal and vegetable fats. The animal fats are prepared from the freshest beef fat or hog fat. That obtained from beef fat is known as oleomargarine," that from hogs' -neutral lard- is chiefly employed in the United States. The vegetable oils are cotton seed oil, arachis oil, and sesamé oil. The vegetable oil must be devoid of free fatty acids and should not possess any unpleasant flavour. Thus, neither maize oil, nor even cotton seed oil, can be used for the finest and best brands of margarine, as the particular flavour of these oils would be noticeable in the finished product.

For the production of oleomargarine, the rough fat is removed from the slaughtered animal as quickly as possible and brought into the works, where it is sorted and the kidney fat is selected. This is carefully washed with warm water and thoroughly cleaned. The cleaned fat is then brought immediately into large, well-aired, artificially cooled rooms to dry and harden, being allowed to hang there suspended from tin hooks for several hours. Another process to secure rapid hardening is to immerse the fat first into iced water.

The hard fat is next cut up and shredded in a shredding machine [various types were shown on the screen] and then ground between rollers. The disintegrated mass is immediately introduced into tin-lined, jacketed: vessels, at a temperature not exceeding 45° C., this temperature being maintained by hot water contained in the jacket.

In large establishments different kinds of vessels are used, several types of which I exhibit here on the screen.

At the temperature of 45°C., only a portion of the fat contained in the animal tissues separates on the top of the comminuted rough fat. The settling and clearing is assisted by scattering salt cver the surface of the melted fat. This melted portion, appropriately termed "premier jus," is carefully syphoned off and run into clean barrels to be sent to the margarine works proper for further treatment. The "premier jus" is not the whole of the fat contained in the charge, but only the first portion that will exude at a temperature of 45°; the remainder of the fat is recovered from the scraps for other purposes which do not interest us here.

If the margarine be produced in the same works, the "premier jus" is allowed to run into shallow, tin-lined trays, arranged in tiers in a cooled room, when the bulk of the "stearine" separates out in a crystalline condition. For the best qualities of margarine, the "premier jus" is remelted, and allowed once more to settle out, after salt has been added, whereby the last traces of membrane and tissue are precipitated. The cleared fat is allowed to run into large vats, in which it stands from three to five days, at a temperature suitable for the crystallisation of the "stearine."

The crystallised mass from the tins is immediately cut up into small pieces weighing about 3 lbs. each. These are wrapped in canvas cloths, and are then put into hydraulic presses. In large works, where the "premier jus" has been allowed to crystallise in huge vats, the whole crystallised mass is stirred up into a homogeneous pulp which is wheeled to the presses and packed into them in small pieces, wrapped in canvas cloth, holding about 3 lbs. each.

[The "premier jus" presses in actual use in the smallest as well as in the largest establishments were here shown on the screen.]

The oleomargarine-" oleo-oil," as it is termed in the United States-runs out into tanks below the presses, to be worked up for margarine. The solid portion which remains in the presses is sold as tallow stearine.

This oleomargarine is the chief raw material for the manufacture of butter substitutes. It is mixed in special churning machines of the various types I illustrate by lantern slides, with vegetable oils and fats and milk.

The milk department forms, therefore, a

substantial portion of the margarine works. On its arrival from the farms the milk must be "pasteurised." As a rule the cream has been taken off before the milk reaches the works, otherwise it is removed by means of a centrifugal machine.

The milk is run, together with the melted oleomargarine and the vegetable oils admixed in accurately weighed off proportions, into churns, in which the whole mass is thoroughly blended. The churning machines consist of oval jacketed vessels, provided with one or two sets of stirring and mixing gear. During the

so that the mass is completely pulverised. The disintegrated globules, after solidifying, somewhat resemble butter granules.

In small works the cooling tanks are built of marble; in larger works they simply consist of large wooden tanks. In other works they form very large storage vessels, built up of tiles.

The solidified margarine is taken out by spades, or by long-handled wooden spoons, and placed in wooden wagons, where the admixed water is allowed to drain off. These wagons are carted to large kneading-machines.

process of churning a constant temperature is maintained by means of steam sent through the jacket of the churn. The object of churning, besides thoroughly mixing the ingredients, is to destroy the tendency of the oleomargarine to crystallise, and to produce a complete emulsion by pulverising the mixture into single globules, such as butter fat forms in milk. When the mass is thoroughly churned, the steam is turned off, and the warm material is cooled by cold water sent through the jacket.

From the churn the cooled margarine is run through wooden shoots into cooling tanks. Whilst running out of the churn the margarine is met in the shutes by a current of ice-cold water, delivered under high pressure,

They consist of huge, circular wooden tables (Fig. 8), which rotate slowly, whilst at the same time a set of conical, fluted, or speciallyshaped rollers move along the top of the revolving tables. The margarine is slowly but thoroughly worked through, SO that the particles become homogeneous throughout the whole mass. At this stage colouring matters are admixed.

The margarine is then salted to taste, and submitted to a further thorough kneading and mixing on a machine similar to the one shown in Fig. 8, or in a specially-constructed churning machine (illustrated by a lantern slide).

The margarine is finally moulded into lumps, pats, rolls, or any other desired shape. [These departments of a margarine works

were

illustrated by lantern slides.] Like butter, margarine contains water; the proportion of this should however not exceed 10 to 12 per cent. in well-made prepara. tions. From the description given and the lantern slides shown, it will have become apparent that, throughout the whole process, the fatty material is not touched by the hands of the operator. Thus the process compares favourably with that employed in small out-ofthe-way dairies, into the minute details of which we had better not inquire.

• The object of the margarine manufacturer is, naturally, to make his product resemble butter as nearly as possible. In order to take away the "tallowy" or exclusively "fatty" taste of the material, some manufacturers, provided the law permit, add butter itself. Others add small quantities of butyric acid, or specially prepared compounds.

An important point is to produce margarine which will froth and "brown" when heated, so that even in cooking the nearest approach to butter is reached. As the property of butter of "browning" and frothing is due to caseïn and milk sugar, it is evident that the more milk is used in the manufacture of margarine, the nearer will the product approximate to butter. This expedient is largely used in this country, but on the Continent, where the law forbids the addition of more than a strictly limited quantity of milk, or its corresponding quantity of butter-fat, a number of curious patents have been taken out for substances purporting to impart the desired property to margarine. Casein and other albuninoids are prominent amongst them. The usual crop of excrescences is not wanting in this industry, and even the use of beeswax and vegetable waxes has been patented, although the employment of such substances must be deprecated, as they seriously reduce the digestibility of margarine.

[Tables giving the estimated production of margarine during 1900, and the quantities and kinds of materials used in the production of margarine in the United States will be found on page 925 of my "Technology and Chemical Analysis of Oils, Fats, and Waxes." Macmillan and Co., 1904.]

Another class of edible fats is represented by lard substitutes. Their manufacture is in many respects similar to that of butter substitutes, although it is much simpler, since lard substitutes contain no water, and merely represent a mixture of fats. The basis of the lard substitutes should be, of course, lard, with

which other oils and fats, such as cotton seed oil and beef fat are intermixed in the melted state.

The enormous quantities of lard substitutes that are produced necessitate rapid cooling of the mass. The simple process of allowing it to cool spontaneously in large vessels is too expensive; hence, special cooling machinery, similar to Petit's cooling wheel (see Lecture IV., Fig. 20) is employed. The wheel of Fig. 20 is replaced by a large hollow cylinder through which cooled brine runs, whilst the sheet of cooled lard thus formed is taken off immediately by means of a pump and filled into tierces.

In the early days of this industry the manufacturers of lard substitutes sailed more closely to the wind than the margarine manufacturer. The lard-substitutes sold under such names as "refined lard," "compound lard," were frequently found to contain no lard whatever, being nothing else than judiciously prepared mixtures of beef stearine-the by-product of the margarine manufacture-and cotton seed oil and other vegetable oils. Here also legislation has had to step in to protect the public.

The detection of cotton seed oil in lard became, therefore, one of the most important problems of the public analyst. A rapid means of detecting it is Halphen's test, which reveals the presence of cotton seed oil by a red colouration. However, too much reliance should not be placed on a rapid test like this, since the adulterator has always been able to keep pace with the latest discoveries of science, and has succeeded in nullifying the indications of this test by treating cotton seed oil in such a manner that it no longer shows the characteristic red colouration. Moreover, some help has accrued to the adulterator through the fact that lard from hogs fed on cotton seed cake exhibits a colour reaction similar to that which lard shows which has actually been adulterated with cotton seed oil.

A third kind of edible fats manufactured on a large scale are vegetable butters and the hard fats derived therefrom, which I comprise under the name "chocolate fats.” Vegetable butters were first made from cocoa nut oil and palm nut oil, and prepared for the Indian market, where the native population are forbidden by their religious tenets to consume animal fats. Latterly this vegetable butter has, under a variety of fancy names, such as "lactine," "vegetaline," 'cocoaline," "laureol," "nucoline," "albene," "palmine," "cocose," &c., found extensive use at

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home in confectionery and in the manufacture of margarine, and—it must be feared-is also finding a growing outlet for adulterating cow's butter. From these vegetable butters "chocolate fats" are obtained. The natural chocolate fat is, of course, cacao butter," which is expressed from the cocoa beans in the course of preparing cocoa. As more cacao butter is obtained from the bean than a properly constituted chocolate should contain, a surplus of cacao butter accumulates in a cocoa works. This surplus is worked up into cheaper kinds of chocolate. Thus a demand has been created for cacao butter. As the natural supply does not suffice, and moreover as cacao butter is the most expensive fat, being even dearer than ordinary cow's butter, there soon arose a demand for a cheap substitute of genuine cacao butter.

Animal fats, such as tallow, are unsuitable for chocolate manufacture, as if not very carefully refined they are apt to impart an unpleasant flavour ("animal flavour") to the finished chocolate.

The best chocolate fat substitutes must, therefore, be prepared from vegetable fats. At present the most suitable substitutes are manufactured from cocoanut and palm nut oils, by removing the softer portions of cocoa nut and palm nut oils in a similar manner as is done in the case of working up the "premier jus." The cocoanut and palm nut oils are allowed to crystallise at a slightly elevated temperature, and the crystallised mass is expressed in hydraulic presses. Whereas in the manufacture of oleomargarine the liquid portion is required, in the present case the hard mass left in the press, termed "cocoanut stearine," or "palm nut stearine," is the desired product.

I show here a number of slabs of "stearines " inanufactured in the manner described. These samples represent the pure cocoanut oil and palm nut oil products, and are therefore white; for market purposes these products are generally coloured yellow, in order to more closely imitate, or even surpass, in appearance genuine cacao butter. Such products are sold under a variety of fancy names, such as "cacaoline," line," &c.

46

COCO

These chocolate fats have the drawback that their melting point is somewhat low. Of course, the more of the softer portion is expressed from the cocoanut oil and palm nut oil, the higher will be the melting point. But since the brands having a high melting point

are somewhat costly, products of lower melting point find ready entrance into chocolate works, and it is therefore easy to understand why so many kinds of chocolate become soft in the pocket, or even when held in the hand.

In order to impart greater hardness to the chocolate fats they in their turn are "stiffened," i.e., adulterated with small quantities of animal fats, such as tallow, tallow-stearine, &c. It has even been stated that Japan wax is admixed in order to raise the melting point. Also mineral waxes like paraffin wax, ceresin, have been admixed for "stiffening" purposes, but these should be totally excluded as they are indigestible.

The preparation of suitable chocolate fats from vegetable fats of a higher melting point than cocoanut oil or palm nut oil would, in my opinion, bring us nearer to the solution of the problem. I would suggest for this purpose the working up of some tropical vegetable fats, such as margosa oil, mowrah seed oil, &c. I have dwelt at some length on the industries of edible oils and fats, as I think that this industry has a great future before it. At present it appears to be in a state of transition. From the large number of patents that are being taken out, it is evident that on all sides strenuous efforts are being made to produce these food stuffs in a palatable, appetising, and at the same time comparatively cheap form.

The extent to which margarine is being consumed in this country may be gathered from the fact that during the year 1902 we imported an amount of margarine valued at £2,569,503. It may be safely assumed that at least an equal quantity is being manufactured at home.

Similarly, the extent to which palm kernel oil and cocoanut oil have been used for edible purposes may be best illustrated by the fact that in the year 1902 about 10,000 tons of these fats were worked up in Europe alone for edible purposes.

Miscellaneous.

CONNECTION BETWEEN EGYPTIAN AND

CELTIC CIVILISATION.*

There is a remarkable connection between the religions, language, customs, and rites of the Ancient Egyptian and those of the ancient Briton. Tacitus

An address delivered to the Section "Costume, Custom, and Folklore" of the Pan-Celtic Congress, 1904, at Carnarvon, by Sir William Preece, K.C.B., F.R.S.