The Progress of Invention in the Nineteenth Century Part 17

_Agricultural chemistry_ is another one of the practical developments of the Nineteenth Century. A hundred years ago the farmer planted his crops, prayed for rain, and trusted to Providence for the increase; he was not infrequently disappointed, but was wholly unable to account for the failure. To-day the intelligent farmer understands the value of nitrogen, has ascertained how it may be fed to his crops through the agency of nitrifying organisms, or he has his soil a.n.a.lyzed at the Agricultural Department, finds out what element it lacks for the crop desired, and in chemically prepared fertilizers supplies that deficiency. The chemical a.n.a.lysis of drinking water has also contributed much to the knowledge of right living and to the avoidance of disease and death, which our forefathers were accustomed to regard as dispensations of Providence.

America has furnished some eminent chemists in the Nineteenth Century, who have made valuable contributions to the science, notably in the field of metallurgy. It is a fact, however, which must be admitted with regret, that America has not in the field of chemical research occupied the leading place she has in mechanical progress. The European laboratory is the birthplace of most modern inventions in the chemical field, and this is so simply by reason of the fact that these more patient investigators have set themselves studiously, systematically and persistently to the work of chemical invention. It is said that some of the large commercial works in Germany have over 100 Ph. D.'s in a single manufacturing establishment, whose work is not directed to the management of the manufacture, but solely to original research, and the making of inventions. The laboratories in such works differ from those in the universities only in being more perfectly equipped, and more sumptuously appointed. The result of this is seen in the fact that in 1899 the United States imported coal tar dyes alone to the extent of $3,799,353, and 5,227,098 pounds of alizarine, most of which came from Germany, and for which we paid a good price, since the German manufacturers control the United States patents. The alizarine dyes are for the most part the artificial kind made by German chemists. Prior to 1869 the red alizarine dye was of plant origin, being obtained from madder root, and it cost $2 a pound. The German chemist produced an artificially made product, which took the place of the madder dye, and was sold at $1.20 a pound. At the end of the patent term (seventeen years) the price fell to 15c. a pound, showing that the product was produced at a profit of more than $1.05 a pound, and as millions of pounds were imported annually, it is estimated that $35,000,000 was the price paid the German chemists for their foresight in combining science with business. Many United States patents granted to foreign chemists are still in force, and the rich reward of their skill is reaped at our expense.

_Discovery of elements._--In the early days of chemical knowledge, fire, air, earth and water const.i.tuted the insignificant category of the elements, which was as faulty in cla.s.sification as it was small in size.

Gradual splitting up of compounds, and an increase in the number of elements, has gone on progressively for some hundreds of years, until to-day the list extends well on to one hundred elementary bodies. Those which belong to the credit of the Nineteenth Century are given in the table following, with the name of the discoverer, and the date of its discovery.

ELEMENTS DISCOVERED IN THE NINETEENTH CENTURY.

ELEMENTS. DISCOVERER. YEAR.

Columbium Hatchett 1801 Tantalum Ekeberg 1802 Iridium Tenant 1803 Osmium Tenant 1803 Cerium Berzelius 1803 Palladium Wollaston 1804 Rhodium Wollaston 1804 Pota.s.sium Davy 1807 Sodium Davy 1807 Barium Davy 1808 Strontium Davy 1808 Calcium Davy 1808 Boron Davy 1808 Iodine Courtois 1811 Cyanogen Gay Lussac 1814 (Comp. rad.) Selenium Berzelius 1817 Cadmium Stromeyer 1817 Lithium Arfvedson 1817 Silicon Berzelius 1823 Zirconium Berzelius 1824 Bromine Balard 1826 Thorium Berzelius 1828 Yttrium Wohler 1828 Glucinum Wohler 1828 Aluminum Wohler 1828 Magnesium Bussey 1829 Vanadium Sefstroem 1830 Lanthanum Mosander 1839 Didymium Mosander 1839 Erbium Mosander 1843 Terbium Mosander 1843 Ruthenium Claus 1845 Rubidium Bunsen 1860 Caesium Bunsen 1860 Thallium Crookes 1862 Indium {Reich } 1863 {Richter} Gallium Boisbaudran 1875 Ytterbium Marignac 1878 Samarium Boisbaudran 1879 Scandium Nilson 1879 Thulium Cleve 1879 Neodymium Welsbach 1885 Praseodymium Welsbach 1885 Gadolinium Marignac 1886 Germanium Winkler 1886 Argon {Raleigh} 1894 {Ramsey } Krypton { Ramsey } 1897 { Travers } Neon {Ramsey } 1898 {Travers} Metargon { Ramsey } 1898 { Travers } Coronium Nasini 1898 Xenon Ramsey 1898 Monium Crookes 1898 Etherion (?) Brush 1898

Whether or not these so-called elements are really true elementary forms of matter, which are absolutely indivisible, is a problem for the chemists of the coming centuries to solve. The cla.s.sification has the approval of the present age. What new elements may be found no one may predict. Mendelejeff's _periodic law_, however, suggests great possibilities in this field. Allotropism, in which the same element will present entirely different physical aspects, is also a significant and suggestive phenomenon, for in it we see carbon appearing at one time as a crude, black and ungainly ma.s.s of coal, and at another it appears as the limpid and flashing diamond. In more than one mind there is a lurking suspicion that there may, after all, be only one form of primordial matter, from which all others are derived by some wondrous play of the atoms, and if so the old idea of the alchemist as to the trans.m.u.tation of metals may not be entirely wrong. The Twentieth Century may give us more light.

CHAPTER XIX.

FOOD AND DRINK.

THE NATURE OF FOOD--THE ROLLER MILL--THE MIDDLINGS PURIFIER-- CULINARY UTENSILS--BREAD MACHINERY--DAIRY APPLIANCES--CENTRIFUGAL MILK SKIMMER--THE CANNING INDUSTRY--STERILIZATION--BUTCHERING AND DRESSING MEATS--OLEOMARGARINE--MANUFACTURE OF SUGAR--THE VACUUM PAN--CENTRIFUGAL FILTER--MODERN DIETETICS AND PATENTED FOODS.

If called upon to name the most important of all factors of human existence, that which underlies and sustains all others, even to life itself, everyone must agree that it is _food_. A remarkable fact in this connection is that all animal life lives and thrives by eating some other thing that is or has been alive, or is the product of organic growth. The vegetarian may pride himself upon his higher ideals of living, but after all his fruit, vegetables, and cereals belong to the great category of living organisms, and are to a certain extent sentient and conscious, for even the plant will turn to the sun. The beasts of the field and fowls of the air live by preying upon other weaker animals and birds, these upon plants and gra.s.ses, and the plants and gra.s.ses upon the decaying mosses and organic mould of the soil, and the mosses upon still lower organisms. The big fish of the sea eat the little fish, the little fish the small fry, and these in turn live upon worms and animalcula, and so on all the way down to protoplasm. Omniverous man, in spite of his boasted civilization and enlightment, not only eats them all, flesh, fowl, fish, grain and plants, but lives exclusively upon them. But he can _only_ live on that which has been produced by the mysterious agency of life, and this furnishes a significant suggestion for the philosopher, for it may be that life itself is only an acc.u.mulated active power or unitary force regenerated in some metamorphic way from vital force stored up in the bacteria of organic food, and necessarily connected therewith in an endless chain of reproductions, and if this be true, the hope of the scientist as to the synthesis of food from its elements must ever remain a philosophic dream, because the scientist cannot create a bacterium.

It has been said that when a man eats meat he thinks meat, and when he eats bread he thinks bread, and when he eats fruit he thinks fruit. It is not clear that the quality or character of man's food is so closely correlated to his thought, but that it has its influence cannot be doubted. It would be safer to say, however, that when a man eats meat he acts meat, and when he eats bread he acts bread, for the muscular energy and aggressive potentiality appear to be much more closely related to the quality of his food than are his thoughts. May it not be that the powerful achievement of the British Empire was directly related to its roast beef? Is not the listless apathy of the Chinese due to a diet of rice? Is not the dominant and masterful power of the lion or the eagle related to a carniverous diet, and the mild and placid temper of the ox the reflex expression of his vegetable food? It is quite true that our potentialities are largely represented by what we eat, and our food therefore becomes a most interesting topic, not only by virtue of its indispensable quality, but by reason also of the possibilities of development in the betterment and elevation of the human race.

From the earliest times even down to the present day man's food has been the same--flesh, fish, cereals, fruits and vegetables. The development of the present century has not extended this category, but it has been directed to an increase in the supply, an improvement in quality, the preservation against decay and waste, and its intelligent selection and adaptation to the special needs of the body. Progress manifests itself in the great field of agriculture, in improved processes and machines for milling; in butchering, packing and handling meats; in preserving and drying fruits; in the preparation of canned goods, in dairy appliances, in cake and cracker machines; in the manufacture of sugar; in the great advance in cookery; in the science of dietetics, and in thousands of minor industries.

In agriculture the raising of grain has extended in the Nineteenth Century to enormous proportions. More than ten thousand patents for plows, as many for reapers, and a proportionate number of planters, cultivators, threshers, and other implements and tools represent the extent to which inventive genius has been directed to the increase of the yield in the harvest field.

This yield in the United States for the year 1898 was:

Corn 1,924,184,660 bushels Wheat 675,148,705 bushels Oats 730,906,643 bushels Rye 25,657,522 bushels Barley 55,792,257 bushels Buckwheat 11,721,927 bushels Potatoes 192,306,338 bushels

[Ill.u.s.tration: FIG. 164.--ROLLER PROCESS OF MAKING FLOUR, WEGMANN'S PATENT.]

For converting the grain into flour, the inventors of the Nineteenth Century have made revolutionary changes. Milling processes within the last twenty-five years have been completely transformed by the introduction of the roller mill and middlings purifier. Formerly two horizontal disk-shaped stones or burrs were employed, the lower one stationary and the upper one revolving in a horizontal plane and crudely crushing the grain between them. In all modern mills these have been entirely displaced by porcelain rolls revolving on horizontal axes and crushing the grain between them. The first of these roller mills is shown in pat. No. 182,250, to Wegmann, Sept. 12, 1876. (See Fig. 164).

The outer rolls _d e_ are pressed against the inner ones _a c_ by a system of weighted levers, and sc.r.a.pers below remove the crushed grain from the periphery of the rolls. Many subsequent improvements have been made, one type of which employs a succession of rolls which act in pairs on the grain one after the other and reduce it by successive gradations.

[Ill.u.s.tration: FIG. 165.--MIDDLINGS PURIFIER.]

The _middlings purifier_, see Fig. 165, comprehends a flat bolt or shaker screen _b_, of bolting cloth, arranged as a horizontal part.i.tion in an enclosing case through which pa.s.ses an upward draft of air produced by suction fan D at the top. This air pa.s.sing up through the bolting screen lifts the bran specks and fuzz from the shaken material as it pa.s.ses downward through the screen, brushes K being arranged below to keep the screen constantly clean. A representative and pioneer type of this machine is seen in Pat. No. 164,050 to George T. Smith, June 1, 1875, from which the view is taken. The useful effect of the roller mill and middlings purifier is to save the most nutritious and valuable part of the grain, which lies between the outer cuticle and the white starch within, and which breaks up in fine grains and is of a golden hue. This portion of the grain was formerly unseparated, and was mixed with the middlings and bran as an inferior product. Modern a.n.a.lysis has disclosed its superior food value, and the roller mill and middlings purifier have provided means by which it can be separated from the bran and incorporated with the flour, thereby greatly adding to its wholesome character and nutritive value, and imparting to the flour the rich creamy tint which characterizes all higher grades.

Minneapolis, Minn., is the great center of the milling interests of the United States. The Pillsbury Mills are located there, and the "Pillsbury A." which is said to be the largest in the world, has a capacity of 7,000 barrels per day.

In 1877-78 disastrous flour dust explosions at Minneapolis brought about the development of the dust collector, for withdrawing from the air of the mills the suspended particles of flour dust, which not only invited explosion, but rendered the air unfit to breathe. Washburn's Pat. No. 213,151, March 11, 1879, is an early example.

The use of crushing rolls has also developed a great variety of new foods, such as cracked wheat, oatmeal grits, etc. These crushing rolls have sometimes been made hollow, and are steam heated, and as they crush the grain they simultaneously effect the cooking or partial conversion of the starch, and the product is known as hominy flake, ceraline, coralline, etc., which furnish popular breakfast foods when served with cream.

[Ill.u.s.tration: FIG. 166.--DOUGH MIXER.]

[Ill.u.s.tration: FIG. 167.--BRAKE, OR KNEADING MACHINE.]

In the field of cookery such activity has been displayed that the average kitchen to-day is a veritable museum of modern inventions. Egg beaters, waffle irons, toasters, broilers, baking pans, apple parers, cherry stoners, cheese cutters, b.u.t.ter workers, coffee mills, corn poppers, cream freezers, dish washers, egg boilers, flour sifters, flat irons, knife sharpeners, can openers, lemon squeezers, potato mashers, meat boilers, nutmeg graters, sausage grinders, and frying pans in endless array; all patented and cl.u.s.tered around the modern cooking range as a central figure, and all presenting points of excellence in the matter of economy and convenience, or the betterment of result. The most extensive application of inventive genius is to be found in the large manufacturing bakeries, which make and sell the millions of pounds of crackers and cakes that fill the bins and shelves of the grocery store. In these manufactories the dough is prepared by a mixer, see Fig.

166, which consists of a spiral working blade revolving in a trough, and capable of handling half a dozen barrels of flour at a time. It is then put through a kneading machine, called a "brake," shown in Fig. 167, and is then ready to be converted into crackers or cakes on a great machine 25 feet long, which finishes the crackers and puts them in the pan ready for the oven. This machine, see Fig. 168, receives the dough at A, where it is coated with flour and flattened into a sheet between rolls. It is then received on a traveling ap.r.o.n B, has the flour brushed off by a rotary brush C, and is then cut into crackers or cakes by vertically reciprocating dies D. At E a series of fingers press the cakes down through the sheet of dough, while the surrounding sc.r.a.ps are raised on a belt F and delivered into a suitable receptacle. The separated cakes at B' are then delivered into pans at G, the pans being fed on the subjacent belt at G'. Such machines, costing nearly a thousand dollars, produce from forty to sixty barrels of crackers a day, enabling them to be sold at about 5 cents a pound at retail.

[Ill.u.s.tration: FIG. 168.--CRACKER AND CAKE MACHINE.]

_Dairy Appliances_ have come in for a large share of attention at the hands of the Nineteenth Century inventor. There are about sixteen million milch cows in the United States, and their contribution to the food stuffs of the day in milk, b.u.t.ter, and cheese is no insignificant factor. There have been over 2,700 patents granted for churns alone, and besides these there are milk coolers, cheese presses, milk skimmers, and even cow milkers. The centrifugal milk skimmer is an interesting type of this cla.s.s of machine. In the old way the milk was set for the cream to rise, which it did slowly from its lighter specific gravity. In the centrifugal skimmer the milk is continuously poured in through a funnel, and the cream runs out continuously through one spout, and the skimmed milk at the other. An ill.u.s.trative type of this machine is shown in Fig. 169. A steam turbine wheel near the base turns a vertical shaft bearing at its upper end a pan which rotates within the outer case. The milk enters through the faucet at the top, and as the pan within rotates, the heavier milk, by its greater specific gravity, is thrown to the outer part of the pan and pa.s.ses out through the larger of the two spouts, while the lighter cream is crowded to the center and pa.s.ses out of the upper spout, which opens into the center of the pan. Patents to Lefeldt & Lentsch, No. 195,515, Sept. 25, 1877, and Houston and Thomson, No. 239,659, April 5, 1881, represent pioneer milk skimmers of this type.

[Ill.u.s.tration: FIG. 169.--CENTRIFUGAL MILK SKIMMER.]

Closely allied to the dairy appliances are the incubator and the bee hive, both of which have claimed a large share of attention, and for which many patents have been granted.

One important and characteristic feature of the present age is the conservation of waste in perishable foodstuffs. Fruits, vegetables, fish and oysters were suitable food to our forefathers only when freshly taken, and any superabundance in supply was either wasted by natural processes of decay, or was fed to the hogs. To-day thousands of patented fruit dryers, cider mills, and preserving processes save this waste and carry over for valuable use through the unproductive winter months these wholesome and valuable articles of diet. Even more important is the _canning industry_, by which not only fruits are maintained in a practically fresh condition for an indefinite time, but oysters, meats, fish, soups, and vegetables are also put up in enormous quant.i.ties.

To-day the grocer's shelves present an endless array of canned tomatoes, peaches, corn, peas, beans, fish, oysters, condensed milk, and potted meats, which const.i.tute probably three-fourths of his staple goods. The tin can is in itself a very insignificant thing, not ent.i.tled to rank with any of the great inventions, but in the every-day campaign of life it is playing its part, and working its influence to an extent that is little dreamed of by the casual observer. It renders possible our military and exploring expeditions; it holds famine and starvation in abeyance; it gives wholesome variety to the diet of both rich and poor; and it transfers the glut of the full season to the want of future days.

Perhaps no single factor of modern life has so great an economic value.

Simple as is the tin can, quite complex machines are required to make it. Originally such machines were operated by hand or foot power, but within the last 25 years power machines have been devised which automatically convert a simple blank or plate of sheet metal into a finished can. Of the many patents granted for such machines the most representative ones are 243,287, 250,096, 267,014, 384,825, 450,624, 465,018, 480,256, 495,426, 489,484.

In the process of putting up canned goods the products are filled into the cans, and the caps, or heads, are soldered on. These caps have a minute hole in the center for the escape of air and steam in the process of cooking and sterilizing, which is conducted as follows: A large number of cans are placed on a tray swung from a crane and the cans lowered into one of a series of great cooking boilers. The cover of the boiler is then closed and fastened by lugs, and steam turned on until the goods in the can are thoroughly heated through. During this process the air and steam escape through the little vent hole from the interior of each can. The cans are then removed, the vent hole closed by a drop of solder, and the goods thus hermetically sealed in a cooked or sterilized condition will keep for a long period of time.

_Sterilizing._--During the last quarter of the century, which has witnessed the growth of the wonderful science of bacteriology, a cla.s.s of devices known as sterilizers has come into existence, whose primary function is to kill the germs of decay by heat. This has had in the canning industry an important commercial application. An example is found in the patent to Shriver, No. 149,256, March 31, 1874. In some of these devices the receptacles containing the food stuffs are in large numbers placed within the heating chamber, and by devices operated from the outside the cans or bottles are opened and shut while within the steam filled chamber. A late ill.u.s.tration is found in patent to Popp _et al._, 524,649, August 14, 1894.

_Butchering and Dressing Meats._--Chicago is the leading city of the world in this industry, and Armour & Co. the largest packers. In the year ending April 1, 1891, they killed and dressed 1,714,000 hogs, 712,000 cattle, and 413,000 sheep. They had 7,900 employees, and 2,250 refrigerating cars were employed for the transportation of their products. The ground area covered by their buildings was fifty acres, giving a floor area of 140 acres, a chill room and cold storage area of forty acres, and a storage capacity of 130,000 tons. In addition to its meat packing business the firm has separate glue works, with buildings covering fifteen acres, where 600 hands are employed, their production in 1890 being 7,000,000 pounds of glue, and 9,500 tons of fertilizer.

Since 1891 this great business has increased until to-day it is said that the army of workmen employed is greater than that of Xenophon, that the firm pays out in wages alone, half a million dollars every month, that four thousand cars are required to carry the products of their factory, and whose business amounts to the enormous sum of one hundred million dollars annually.

[Ill.u.s.tration: FIG. 170.--KILLING AND DRESSING PORK.]

There are from forty to fifty million cattle raised in the United States, and an equal amount of sheep. The number of hogs raised has diminished somewhat in the past few years, but from 1889 to 1892 more than fifty million were maintained. The process of slaughtering and dressing pork, as practiced to-day, is a continuous one, and is well ill.u.s.trated in Fig. 170, in 13 operations. The animals are driven into a catching pen at 1, where they are strung up by one leg, and secured to a traveling pulley on an overhead rail. At 2 the animal is instantly killed by a knife thrust that reaches the heart; at 3 he is dumped into a vat of scalding water, kept hot by steam pipes, where the hair is loosened (see detail view Fig. 171). A series of oscillating curved arms, shaped like a horse hay-rake, dips the carca.s.s out of the scalding vat and deposits it upon the table 4 (Fig. 170), where it is attached to an endless cable that drags it through a sc.r.a.ping machine at 5. This takes off the hair, as shown in detail view Fig. 172. At 6 (Fig. 170) the remnants of hair are removed by hand, and at 7 the skin is washed clean. At 8 the carca.s.s is inspected, and the throat cut across; at 9 the entrails are removed; at 10 the leaf lard is taken out; at 11 the heads are severed and tongues removed; at 12 the carca.s.s is split into halves, and at 13 the sections are ready to be run into the cooling room.

[Ill.u.s.tration: FIG. 171.--SCALDING TO LOOSEN THE HAIR.]

[Ill.u.s.tration: FIG. 172.--Sc.r.a.pING OFF THE HAIR BY MACHINERY.]

From 10 to 15 minutes only are required to convert the living animal into dressed pork. Every part of the animal is utilized. The lungs, heart, liver and tr.i.m.m.i.n.gs go to the sausage department. The feet are pickled or converted into glue. The intestines are stripped and cleaned for sausage casings. The soft parts of the head are made into so-called cheese, and the fat is rendered into lard. The finer quality of bristles goes to the brushmakers, and the balance is used by upholsterers for mixing with horse hair. The blood is largely used for making alb.u.men for photographic uses, as well as in sugar refining, for meat extracts, and for fertilizers. The bones are ground for fertilizer, and even the tank waters are concentrated and used for the same purpose.

_Oleomargarine._--About 1868 M. Mege, a French chemist, commissioned by his government to investigate certain questions of domestic economy, was led into the study of beef fat, and to make comparisons of the same with b.u.t.ter. He found that when cows were deprived of food containing fat they still continued to give milk yielding cream or fatty products. He therefore concluded that the stored-up fat in the animal was then converted into cream, and that it was practicable, therefore, to convert beef fat into b.u.t.ter fat. Physiology taught that in the living animal the change was wrought through the withdrawal of the larger part of the stearine by respiratory combustion, while the oleomargarine was secreted by the milk glands, and its conversion into butyric oleomargarine effected in the udder under the influence of the mammary pepsin. In the process of making b.u.t.ter by the ordinary method of churning the cream, the finely divided b.u.t.ter fat globules are united into ma.s.ses, containing by mechanical admixture from 12 to 14 per cent. of water or b.u.t.termilk carrying a fractional per cent. of cheese. This b.u.t.termilk contributes somewhat to the flavor, but at the same time furnishes a ferment which ultimately spoils the b.u.t.ter by making it rancid. It is a purely accidental ingredient, and one not at all desirable. To some extent the same may be said of the soluble fats which give to the b.u.t.ter its variable though characteristic flavor. They are unstable compounds, decomposing readily, and furnish the acrid products which make "strong"

b.u.t.ter. M. Mege sought to imitate the natural process of b.u.t.ter-making, which was first to separate from the oily fat of suet the cellular tissue and excess of stearine or hard fat; second, to add to the oil a sufficient proportion of butyric compounds to give the necessary flavor, and third, to consolidate the b.u.t.ter fat without grain, and to add at the same time the requisite proportion of water, salt, and coloring matter, to make a compound substantially the same in composition, flavor, and appearance, as b.u.t.ter churned from the cream, and all this without adding to the original fat anything dietetically objectionable, and without submitting it to any process capable of impairing its wholesome quality. These objects were fairly obtained in the product known as oleomargarine, the United States patent for which was granted to Mege Dec. 30, 1873, No. 146,012.

The process in brief is to take fresh beef fat, which is first chopped up and thoroughly washed. It is then placed in melting tanks at a temperature of 122 to 124 F, and the clear yellow oil is drawn off and allowed to stand until it granulates. The fat is then packed in cloths set in moulds and a slowly increasing pressure squeezes out the pure amber colored oil, leaving the stearine behind. This sweet and pure yellow oil is then churned with milk for 20 minutes until the oil is completely broken up, and a small quant.i.ty of annato, a vegetable coloring matter, is added to give a yellow color. The product is then cooled in ice, and after a second churning with milk it is salted and finished like b.u.t.ter. Chemical a.n.a.lysis shows oleomargarine to have substantially the same const.i.tuents and in almost the identical proportions of pure b.u.t.ter. It is equally wholesome, and while it does not have the same rich flavor, it has the advantage that it keeps better, and is not so liable to become rancid or strong. The oleomargarine industry is closely related to the beef packing industries of the United States, and its growth has been enormous. Notwithstanding the stringent laws on the subject, much of the oleomargarine made is sold for, and by the average purchaser is not distinguishable from, pure b.u.t.ter. In 1899 there were 80,495,628 pounds of oleomargarine made in the United States, or more than a pound for every man, woman, and child in the country. The internal revenue tax paid on it was $1,609,912.56.

The exports for the year 1899 were 5,549,322 pounds of the artificial b.u.t.ter, and 142,390,492 pounds of the oleo oil prepared for conversion into the complete product by simply churning with milk.

_Sugar._--Sugar-cane, beets, and the sap of the maple const.i.tute the sources from which sugar is extracted, but the cane furnishes by far the largest supply. When crushed between rolls it yields 65 per cent. of its weight as juice, and 18 per cent. of this juice is sugar. It is concentrated by evaporation at a low temperature, the crystallized portion being known as "raw" or brown sugar, which is subsequently refined, while the uncrystallized portion forms mola.s.ses.

[Ill.u.s.tration: FIG. 173.--VACUUM PAN FOR EVAPORATING THE SYRUP TO PRODUCE SUGAR.]

In the process of refining, 2 or 3 parts of raw sugar, with one of water containing a little lime, ground bone black, and the serum of bullocks'