Puslapio vaizdai
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from Egypt, and more recently from Bombay and the Levant, to yield edible cotton seed oil, soapmaking oil, and cotton seed cake. Here also is imported the rape seed from India, the castor seed, and in smaller quantities some other seeds, that have helped to create the vast seed-crushing industry which has reached, through the inventions of two Englishmen, Bramah and Armstrong, a completeness of mechanical detail which has maintained the supremacy of our country in this industry.

Enormous as are the quantities that are thus imported and worked up in this country, still they represent only a small quantity of the oleaginous seeds that nature offers us. Thus, India, China, and Japan possess vast stores of seeds, yielding safflower oil, bean oil, tung oil (Japanese or Chinese wood oil), and other oils, which are awaiting industrial application. All that appears to be required is better communication to stimulate the cultivation of oleaginous seeds.

Vaster still are the stores of hard vegetable fats which tropical countries such as India, the Sunda Islands, South America, and tropical Africa are able to furnish. Hitherto only two or three kinds of vegetable fats have found extensive use in this country, namely, cocoanut oil and the two oils obtained from the palm tree-palm oil and palm kernel oil. Smaller quantities only of other fats, such as Mowrah seed oil and Mahwah butter, reach this country, whereas the Continent of Europe seems to be less conservative in the choice of its raw materials. Thus, Chinese vegetable tallow and shea butter are chiefly worked up in Marseilles and in the North of Europe, whereas only comparatively small quantities reach this country. The vast stores which the Malayan Archipelago alone could furnish seem to be practically unknown to the majority of manufacturers.

This is not the place to examine whether this feature is due to the want of communication in India, or to the want of enterprise and the indolence of the natives. In the case of palm oil, at least, which could certainly be employed in much larger quantities, it is owing to the deadly climate and to the laziness of the negro that one of the most admirable raw materials of our staple industries cannot be obtained at a price which should be much lower than that at which it is supplied at present.

Nor does it appear that those who are most interested in the shipping trade of the West Coast of Africa take such steps as are required

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to imitate the example of Germany who, since she entered into the possession of colonies on the West Coast of Africa, has taken the most energetic interest in promoting the cultivation of the palm tree, which yields one of the chief exports of the Guinea Coast. We may confidently expect that our Imperial Institute will, like similar institutions in France, Germany, and Holland, help in arousing the interest of the manufacturer, and place before him the treasures that are still lying unused in our Colonies.

[Here a large collection of oil and fatyielding seeds was shown. Most of the Indian specimens had been contributed by the Imperial Institute through the kindness of Prof. Dunstan.]

With respect to the marine animal oils, it is but natural that they should be produced in this country on a very extensive scale. The industry of medicinal cod oil is naturally small in extent, whereas the industry of commercial cod oil and fish oils has received an enormous impetus during recent years, through the replacement of the old sailing craft, which had to keep out at sea for some days before a sufficient amount of livers were collected, by fast steamers which bring in their nettings within one day.

Thus we obtain large quantities of oil; and yet these do not seem to suffice, for very considerable quantities of cod oil are imported from Newfoundland, as also fish oil from Japan. The large representative collection of seal, whale, and allied oils which I place before you will give an idea as to the extent this branch of the oil industry occupies in this country.

Turning to the solid fats of the animal kingdom, the production of lard, of tallow, and of butter in this country is but an insignificant one as compared with the quantities we import. The changes in the source of supply that have occurred during the last 20 years do not appear to be well-known. The name of "Petersburg yellow candle tallow," once a household word with the tallow chandler and soapmaker, has passed into the limbo of things that were. Russia, instead of exporting tallow, has become a large importer of Australian tallow. Up till a few years ago, the United States of America have been supplying this market with a large amount of its requirements; but it seems as if America will in a few years drop out of the rank of those countries which can spare any supplies for us.

Australia and New Zealand, in conjunction with the Argentine, are now our chief sources of supply of this indispensable raw material for our industries. The high prices that were the result of the long-lasting drought in Australia are bound to stimulate an increased production, and it may be hoped that under the beneficent rule that has recently gained its predominance in South Africa, the Transvaal and Orange Colony will become great cattleraising centres.

Owing to the large consumption of meat in this country, the amount of "home tallow" (home-rendered tallow) is very considerable. It seems, however, impossible to state even approximately the amount so produced, as the most experienced dealers are at a loss to know at what figure to place the home production.

From the first table given above may be gathered the enormous amount of butter that is imported into this country. Not only are Holland, Denmark, and Sweden competitors in this market, but even Siberia and Australia have entered the lists, and it must be expected that, under the stimulus of the expanding consumption, improvements in cold storage methods will permit the products of the Antipodes to reach us in the same state of freshness as they arrive from neighbouring

countries.

A few words only can be said about lard. It is well known that our chief supplies come from the United States, where as many as 10,000 hogs are killed per day in some of the enormous packing houses, and worked up on the same day into all the products that can be obtained from them. Owing to the desire on the part of the manufacturer to produce the largest possible quantity of lard, the word "lard" has ceased to have its old meaning, i.e., “fat from the leaf," and in the majority of cases it must be understood to mean the fat that is derived from any part or all parts of the hog.

The methods of producing fatty oils date back to the remotest times in the history of mankind. It is therefore obvious that the technical appliances used even at the present day range from the simplest contrivances constructed by the natives of Asia and Africa up to the most elaborate machinery employed in this country.

Time does not permit me to present here the development of this industry from the early dawn of civilisation, and I must content myself with contrasting by means of a few slides (shown on the screen) the present-day manufacture of palm oil in West Africa and the Philip

pines, and of the Chinese bean oil in Manchuria, with the methods in vogue in this country. The modern processes divide themselves naturally into two classes,

I. Recovery of oils by expression.

II. Recovery of oils by extraction with

volatile solvents.

Common to both processes is the machinery required for the preliminary treatment of the fruit or seeds.

1.-RECOVERY OF OILS BY EXPRESSION.

The recovery of oils by expression has reached the very complete system in vogue nowadays in the best equipped establishments through the invention of the hydraulic press and the accumulator, to which reference has been made already.

Since the machinery required for the preliminary treatment of the fruit or seeds must vary with each particular kind of fruit or seed, the preparatory operations for laying bare the fat-containing cells of, e.g., cocoanuts, will naturally differ from those necessary in the case of linseed. I will therefore illustrate, by means of a series of lantern slides, the preliminary treatment of a few kinds of fruits and seeds, such as palm kernels, copra (dried cocoanut kernels), arachis nuts, castor seeds, cotton seed, linseed, and safflower seed.

[The following lantern slides were shown :Screen and magnetic separator for palm kernels and copra; palm kernel and copra breaking mills, breaking rollers for copra, arachis nut decorticator, separator for decorticated arachis nuts, decorticator for castor seed, cotton seed delinting machine, cotton seed decorticators (different types; American and English machines), linseed screen, and plants illustrating the working of the various machines described. Samples of the different seeds and various kinds thereof (especially various kinds of linseed and cotton seed) were also shown.]

The immense quantities in which smaller seeds such as cotton seed or linseed are crushed, necessitated the construction of special warehouses or silos, where the seeds are stored in a similar manner as grain is warehoused, the seed being frequently turned so as not to heat spontaneously, since heating acts detrimentally on the quality of the oil.

The seed entering the oil mill from the silos is reduced to "meal" on passing through crushing machinery of the kind I show in the lantern slide representing the AngloAmerican five- roller machine. The comminuted seed is either expressed in this state

(production of oils for edible purposes) or conveyed by means of an elevator into a kettle in which the seed is warmed (production of oils for manufacturing purposes) by means steam, which causes the cells to burst rapidly, renders the oil more fluid, and perhaps also helps to coagulate some albuminoid matter, all these operations combining to facilitate the subsequent moulding of the meal into cakes.

An exactly-measured quantity of heated seed then falls out, on opening a slide, and drops into a measuring-box. On being drawn forward, this allows the seed to fall on to a press-cloth of the desired shape of the oil-cake. By a preliminary pressing sufficient consistence is given to the cake so that it can be carried, wrapped in the cloth, to the hydraulic press. This consists, in the Anglo-American system of seed-crushing, of an open press, fitted with about 16 iron press plates, between which the cakes are inserted by workmen. The press is packed with cakes until full; the ram is then driven up by machinery, at first with the help of an accumulator, and finally by hydraulic pumps. The oil exudes from the meal, drains off, and is collected in tanks below the press or set of presses which are generally arranged in the Anglo-American system in a battery of four presses. After releasing the pressure the cakes are taken out, and the edges, which are soft and oily, are trimmed off in a cake-paring machine. Obviously, the cakes retain a certain quantity of oil, and in the case of those seeds which contain a large amount of oil, such as castor seed, a second expression is required.

The hard cakes are, therefore, broken up in a cake-breaking machine, whilst the softer cake-parings are triturated in a special machine. In some cases an edge-runner mill is used for the same purpose. (All the machines mentioned, as also an ensemble of an oil mill plant, were shown in lantern slides.)

The first expression of seeds that are rich in oil, such as those containing more than 40 per cent., leads to some difficulties in the open hydraulic press, since the oily meal causes "spueing," ie., the soft mass is apt to exude through the cloth. Hence, in modern installations, seeds of this kind are frequently expressed in a 'clodding press," i.e. a hydraulic press provided with a circular box or cage into which the material is filled. The box is either constructed of metal staves (vertical steel bars), held together by a number of steel rings, or consists of a cylinder having a large number

of perforations. These presses, generally worked in sets of two, or three, or more, have a seed kettle fixed on the top of the press (see Figs. 1, 2); the kettle is provided with an opening or openings, corresponding to the chamber or chambers in the heads of the press or presses. These chambers can be closed at the top and bottom by slides, actuated by levers, and are designed to contain so much meal as is required to form one cake. The measured charge of meal is then FIG. 1.

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allowed to fall into the press box, and covered with a circular metal plate. This operation is repeated until the press is full, when hydraulic pressure is applied, and a ram forces the box against the sliding block at the head of the press. The oil exudes, and the meal, pressed into circular cakes, is ready for the second expression. After releasing the pressure and removing the sliding block, the cakes are forced out by the hydraulic ram. They are then broken into meal, and subjected to a second expression in the Anglo-American hydraulic press, described already.

Modern improvements in the mechanical part of the process dispense even for the

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