( Originally Published 1906 )
Comparison of Foreign and Domestic Glues. — A considerable proportion of the glue consumed annually in the United States is of foreign manufacture and, were not the tariff duty on these goods so high as to be almost prohibitive in many instances, it is to be feared that some grades would supplant the corresponding domestic in certain classes of work. The contention, advanced by many, that foreign glues are invariably productive of better results than the domestic goods of equal test-strength, is entirely too broad and sweeping. Yet it must be admitted that there are times when a well made 1 7/8 foreign glue will do the work of a poorly made 1 /1/2 domestic.
Much uncertainty exists in the minds of the glue-consuming public as to whether the vaunted superiority of foreign glue over our own product is founded on imagination or on fact. The radical difference in appearance between foreign and domestic glues has its origin in the fact that the stock from which the former are made is selected with the greatest care. In addition it is frequently hand-picked, the laborious process of removing physical imperfections of the stock by hand being reckoned as nought compared with the possibility of producing an off-grade of glue through neglect of this precaution. Labor conditions are such in England and on the Continent that it is possible to subject both stock and glue-liquor to operations precluded by the high cost of labor in the United States. Where the European manufacturer can avail himself, at a trifling cost, of the services of the aged and infirm of the locality in which his factory is situate, for the purpose of hand-picking glue-stock, the same labor would command many times the price in the United States and hence the increased cost of production would speedily place beyond the pale of competition the manufacturer who sought to take advantage of such process.
Factors other than the initial treatment of stock operate to create a difference between foreign and domestic glues. The glue-liquors are, as a rule, subjected to processes of clarification or those tending to precipitate the viscous, non-adhesive elements. For this reason, the majority of foreign glues are markedly translucent, if not actually transparent. The viscosity of their solutions is lower than the subsequent jelly-strength would indicate, as is the case with our acid-treated glues.
It is to be borne in mind that glue is glue, the world over, and that the manufacturer, abroad, is subject to the same limitations in production as the manufacturer in this country. The author is not in a position to state whether or not all European manufacturers sell their glue on test. If one is to judge from the contributions of foreign authors to the literature of the subject, each manufacturer employs an individual test-system which certainly must fail of enlightening him as to the commercial fitness of his product, determined by the requirement of the American consumer. This view is materially strengthened by applying the test to various makes and grades of imported glues, when the discrepancies in price between those of identical strength and quality would indicate that the price is governed altogether by cost of production. A German manufacturer will frequently demand a price for a glue testing 1 3/4 for which price an English manufacturer will offer one of 1 1/2 test. Many other examples might be cited in confirmation of the theory that there is not a suggestion of test-uniformity among European manufacturers.
Save with the higher, more expensive grades, the boasted uniformity of foreign glues is largely a myth. For four years the author has tested regular monthly shipments from divers European factories, and there have been frequently variations corresponding to two domestic grades. Even the higher grades vary at times. It may be safely asserted that there is no economy in using a low-grade imported product in preference to a domestic. A foreign glue of 1 7/8 strength will usually cost from eight to nine cents per pound here, when the duty and freight have been added to the quoted price. A clever buyer will procure a domestic glue of at least 1 1/2 strength for the same money.
In certain classes of work, however, particularly where the glue is to be worked in conjunction with unstable chemicals, or for finishing delicate fabrics, the use of foreign glues is of material advantage, if not imperative. All substances tending to affect the chemicals have been removed through the initial treatment of the stock or the very processes of clarification or precipitation before alluded to. Again, their viscosities being low as a result of these treatments, foreign glues are better adapted to sizing work than are many domestic grades.
These exceptions granted, it is an open question whether foreign glues of all grades are more economical in actual work than the corresponding domestic grades. Personally, the writer thinks not. Certain domestic glues, those made by the Michigan Carbon Works, for example, are identical in appearance with some grades of foreign, for the reason that they are made in just the same way. As a result, the price of these products is far higher than that of the regular domestic of the same grade. Thus, the 1 5/8 of this make commands a price averaging twelve cents per pound, for which could be obtained a straight hide 11 glue. The very fact that such glues are produced in this country bears out the contention that it is not owing to any superiority in skill, but rather to variance in the methods of treating the stock and liquors, that foreign manufacturers pro-duce an article so different in appearance and general working properties from American.
Granting, further, the claim that the 1 5/8 glue of the above-mentioned make will do the work of the 1 1/4 hide obtainable for the same money, the latter is apt to prove much more uniform in the end. While clarification and other processes doubtless render the finished glue better for such purposes as sizing, these processes are apt to deprive the article of much valuable binding material in the endeavor to remove viscous, non-adhesive elements. While conceding the superiority of a foreign glue as compared with a domestic bone product of even greater strength, the author holds that if a careful comparison be made between the average foreign and a domestic hide glue of equal strength, in actual work, the verdict will be in favor of the latter, as it is far cheaper and if properly applied will do as good work, if not better. Few, if any, foreign glues equal the domestic A Extras or even the 1 Extras. A foreign glue, testing 1 X, is worth in this market fourteen or fifteen cents per pound, a price which will procure a domestic A Extra superior in every way.
It must not be inferred that all foreign glues are alike. While they have many characteristics in common, such as clearness and extreme hardness, they are in a measure distinguishable according to the country which produces them. The author's experience with foreign glues has been limited to the examination of English, French, Italian, and German of a great variety of makes. The Italian and French correspond in general appearance and behavior. The majority of German are widely different from any other make, while the English may be regarded as most nearly corresponding with some of our domestic product. It would seem that to Russia belongs the credit of first producing opaque or colored glues, since glues of this class are designated Russian even though made in Germany or elsewhere. Similarly, much Scotch glue is manufactured in France, and a grade of Irish glue is produced in Lincolnshire, England. It is thus seen that some of these designations refer to particular brands of glue, rather than indicating the country producing them.
The United States produces but little gelatine of good quality, the bulk of that consumed here being imported. Domestic gelatines lack the purity of the foreign product. They are rather too gluey, and are deficient in strength (water-absorbing quality). Germany and France lead in the production of gelatine applicable to the arts, while England has produced several edible varieties of great merit. French and Italian gelatines, as a rule, are stronger than German. That American manufacturers will, in the near future, produce goods of equal merit, is a certainty. Already the 00 and 000 gelatines of the Michigan Carbon Works are achieving prominence, while some of the Western packing-houses are producing gelatines of great strength. Although the products alluded to are fairly pure and strong there is considerable room for their improvement.
Since foreign glues of every make exhibit certain characteristics in common, it is to be inferred that the higher grades owe their superiority to differences in stock rather than in methods of preparation and boiling. This contention is supported by the fact that at certain factories in the United States, glue-makers are employed whose experience and training have been mainly European, and particularly, German. As a result, the product of these factories is similar in appearance and working properties to foreign-made glue, and differs from it in that it is invariably two or three grades stronger. This added strength can be due only to the superiority of American stock. Thus, an Indiana factory employing a German glue-maker produces a pale yellow ribbon glue well adapted to silk finishing and the preparation of gummed labels. This glue, which is identical with several varieties of German, so far as appearance is concerned, is far stronger than any German glue that can be bought at the price (nine and one half cents) in this market. The other glues produced at these works are characterized by the clearness of the foreign product with the strength of the average domestic hide glue. Such are superior to the corresponding imported grades in that they are better pre-served.
On the other hand, differences characterizing domestic glues are due to variations of process as well as of stock. The problem of a proper stock supply is be-coming a serious one with many of our factories. The markets are closely watched by the representatives of many, and stock purchased in every quarter of the country. So great is the demand, that stock of inferior quality is frequently purchased and the skill of the glue-maker depended upon to produce a good article. This will account in large measure for the frequent variations in test of the same grade of glue. It is to be assumed that even a greater stringency exists abroad, where packing industries as well as tanning are not so extensive as in this country. Despite this, stock imported from Europe is at times offered in this market, while that coming from Argentina and other South American countries is commonly employed for glue making both here and abroad. Contrary to popular belief, stock is at as great a premium with the packing-houses operating glue works as with the smaller producer. Since each department of such a concern is conducted as a separate business, it is necessary for the glue department to purchase the stock from the other departments, with the result that it is frequently more profitable to buy in the open market. Ohio, Connecticut, and Massachusetts are almost inexhaustible sources of stock supply. Newark, N. J., a veritable center of the leather industry, furnishes considerable glue-stock, as do the isolated tanneries throughout the country.
So varied is the stock in character, that it is possible for the American glue-maker, through individuality in treatment, to produce a characteristic and distinctive glue. Thus the Baeder Adamson, Armour, Swift, Cudahy, Nelson Morris, American Tanners, Delaney, Anglo-American, Cooper, and Delaware, product exhibit individual characteristics enabling the experienced to identify them with comparative ease. On the other hand, a brown medium-priced foreign glue might readily be the output of any one of a score of European factories, for all that appearance or test tells. Given a specific requirement, almost any imported glue of requisite strength will answer, whether made in Germany, France, England, or Italy. The same rule applies to imported gelatines, so similar are the corresponding grades produced by each country.
It is well known that the modus operandi in almost every European industry is largely governed by tradition. In an industry such as glue making, where the art is frequently transmitted from father to son, tradition plays a most important part and its influence is to be observed even in this country in the manufacture of glue. It is to be inferred that, because of tradition, European glues will continue the same, time without end. The American trained glue-maker, though as a rule conservative, is more prone to experiment than is his European cousin; and since development of any industry is dependent upon experiment, glue making in the United States will doubtless eventually be reduced to almost an exact science.
Lack of space forbids the description of all the varieties of imported glue examined by the author, and hence discussion, is limited to such as are typical.
English Glues. While exhibiting certain characteristics in common with those produced upon the Continent, glues made in England differ somewhat and may be considered as intermediate between domestic glues and those manufactured in Continental Europe. Whether this is due to differences in stock or in treatment is an open question. As it is, some English ground hide glues closely resemble our own higher grades, and certain ground bone glues of English manufacture have their domestic prototypes in the C X glue of Armour & Co. and of other American factories.
Probably the best known English glue in this market is the "Walsall." This appears in the form of fairly thin sheets of good texture, brownish yellow in color and bearing the marks of the net. This may be regarded as the type of high-grade English glue and its merit is attested by the fact that it is extensively imitated. It is applied largely in the manufacture of matches and is also well adapted to joiner-work.
A ground hide glue produced by the Grove Chemical & Fertilizer Works closely resembles American ground hide glues. This concern also manufactures weak bone glues very similar to our own, including a "concentrated size powder," which is regularly duplicated in this country under the less fantastic name of powdered bone glue.
Other types of English glue are the Crown English Crown No. 1, D. F., etc., made by Duche Freres who maintain extensive works both in England and in France. The "Star and Anchor" glue produced by this concern is typical of either French or English glues of a certain class. It finds an extensive use in this country, particularly in the manufacture of carriages, in which industry there exists a rabid prejudice in favor of foreign glues.
Although some English glues are described by the makers as free from acid or alkali and even grease, such is not always the case. Some show at times as much as 0.5 per cent mineral acidity and appreciable quantities of grease. These facts are not cited with a view to disparaging the product. It is a matter of extreme difficulty to produce a glue absolutely free from alkali, acid, or grease. Others, again, are remarkably beautiful in appearance but extremely weak, testing No. 2. They are pale yellow sheets, very clear and transparent, with high luster. A working trial of these glues is fraught with extreme disappointment. It cannot be stated, with any degree of finality, that their lack of strength is due to the very processes that have contributed to their fine texture and appearance, but it is to be inferred that such is the case.
Irish Glues. — Two grades of Irish glue are very well known in this market — the Block C. and the Block C. L. The former is made in Ireland, while the latter is produced in Lincolnshire England, as the initial, L, de-notes. Both are high-grade glues. The Block C. appears in the market in the form of broad, seal-brown sheets, cut fairly thin and prominently marked by the nets. It tests about 1 X on the average and, though considerably clearer, is otherwise identical with a medium, thin-cut, domestic glue, made from straight hide. The Block C. L. is of a somewhat different shade and thicker cut. As a rule, it is very greasy, much more so than any foreign glue examined by the author. Both Block C. and Block C. L. are used in the manufacture of matches, and it is claimed by some that the grease of the latter renders it even more valuable than the former for this purpose. It would seem, however, that this grease is a serious defect in a glue intended for match-composition.
There is a so-called Irish glue, designated "Irish, G. B.," appearing in this market. It bears no resemblance to either of the foregoing grades and, in fact, is not Irish glue at all, being produced in England in an abortive endeavor to imitate the "Walsall" glue. A sample, figuring in a lawsuit, was examined by the author. It is in sheet form, very pale of color, and appears to be made largely from skin-stock. The sample was strongly alkaline in reaction and chromate of lead was present in the ash, resulting from the probable addition of a lead salt to impart factitious weight and a chromate to enhance the drying properties of the glue.
Scotch Glue. — Several samples of this variety of glue have come to the writer's notice, one made in England, another produced in France, and still another of German manufacture. Scotch glue is characterized by extreme darkness of color. Held away from the light, it appears to be almost black; but if held up to the light, the sheet is seen to be of a deep red or claret color. The glue is in the form of sheets, seven to eight inches square and about one-half inch thick. So tough is this glue, that sharp blows with a hammer are necessary to break it, and if one were to judge by the fracture alone, it would be considered of great strength. It seldom tests more than 1, however, and more often l 7/8 or No. 2. Scotch glue is of such thickness that it is necessary to soak it twenty-four hours before it will melt properly. Of the samples examined by the author, that of French manufacture was the best. This tested l 3/4, but owing to the peculiar character of foreign-made glues held a wood-joint so strongly that crushing blows with a hammer failed to separate the two pieces for some little time.
German Glues. — While Germany produces glues in far greater variety than-other European countries, her product is, as a rule, inferior in quality. This is doubt-less due in part to differences in stock as well as in methods of manipulation. The fact remains, however, that despite the alluring superlatives employed in the description of the product on the printed labels attached to the sheets of each make, a large proportion of German glues is poorly made. It would seem that Germany excels in the manufacture of medium quality bone glues. The hide glues, or the mixed bone and hide, cannot compare with our own product either in strength or in keeping qualities. Those that are at all serviceable cost from seventeen to twenty cents per pound in this market — a price which is ridiculously high.
As has been pointed out, the printed guarantees of the manufacturer are not always substantiated by test. German glues may be roughly divided into two classes, "Superior" and "Extra Superior," and frequently the former are of better quality than the latter. To these adjectives there are added such as "Fett-frei" (grease-free), "Sauer-frei" (acid-free), etc. The glue is also described either as "Leder Leim" (hide glue) or "Knochen Leim" (bone glue). Many of those described as pure hide contain considerable bone liquor, and some described as acid- or alkali-free react strongly with litmus for one or the other of these conditions.
German glues are usually in the form of sheets about five inches long by two wide. In thickness, these vary from a quarter to a half an inch. The poorer grades are usually very difficult of fracture, breaking in long splintery, strips. The better varieties are not so thick cut. A chocolate brown is the prevailing color, although the higher grades range through the shades of yellow. Those that can be purchased in this market for seven or eight cents per pound seldom test over 1 3/4 and are more likely to test 1 7/8 and No. 2.
Cologne glue may be regarded as typical of the German product. Originally, this was a very fine article, but of late gears has markedly deteriorated owing to extensive imitation in which the original glue formula has been entirely lost sight of. So superior was the quality of this glue and so general its recognition that it has needed but the term "Cologne" to effect the speedy sale of many a spurious grade of glue. The genuine article is in the form of small, square cakes, very thick and extremely hard. It is manufactured from scraps of hide and skin, which, after liming, are bleached; and in order to obtain as clear a jelly as possible, certain portions of the glue-stock are rejected after bleaching and worked into darker glue. The fact that the genuine is characterized by great clearness of jelly has led to its extensive imitation. Bone glues are frequently described and sold as Cologne glue, even by German manufacturers themselves, coming into the market as "Kolnische Knochen Leim." Such characterization is in itself sufficient to warn the prospective purchaser that he is offered a spurious article.
Many of the cheaper grades of German glue lack the necessary keeping qualities to encourage their extensive use in this country. Even some of the higher grades are insufficiently preserved, while over-liming frequently to be observed in both. This latter defect noticeable chiefly in glues of great clearness and paleness of color, yielding very clear jellies, and is doubt-less due in many instances to the attempt to bleach the stock after liming through the agency of milk of lime. Pale yellow, clear, bone glues owe both clearness and color to treatment of the liquors with sulphurous acid gas. These glues, while very fine in appearance, are extremely weak in test.
French Glues. — Glues of French manufacture are far stronger and better in quality than other European glues obtainable for the same price in this market. The lower grades are of great purity and test from one to two grades (Cooper) higher than the corresponding German or even English product. A peculiarity of French glues is that, save for the cheaper varieties, which are invariably dark in color, they occupy a position intermediate between glues and gelatines. Were they cut thinner, many of the medium grades would pass for low-quality gelatines.
The Jacquet Coignet glues are unquestionably the highest type of French product and, in a sense, of any glues produced. They embody the purity of the average commercial gelatine with all the strength and adhesiveness of a high-class hide glue. A favorite grade, much used by representative cabinet-makers in this country, appears in sheets about eight inches square and a quarter of an inch thick, medium yellow in color. This tests, as a rule, 1 Extra, and is conceded to be without an equal in binding two pieces of wood.
The glues and gelatines produced by Messrs. Tancrede & Cie. are more truly representative of the French product than the above, since the J. Coignet are of such merit as to place them beyond comparison with other makes without too great a disparagement of the latter. Several varieties of glue are produced by Tancrede, the "Colle sans Marque," "Ecossais," "Soleil," and "Medaille."
The "Colle sans Marque" (Unbranded glue) is the weakest of these glues, testing on an average 1 7/8, although sometimes running as high as 1 3/4. This variation in test is due to the fact that at times the glue is shipped fresher than at others. The color of this glue is dark brown and the sheets are from six to seven inches square. The "Ecossais" (Scotch glue) has already been de-scribed in the foregoing discussion of glues of this name. The "Soleil" (Sun) and "Medaille" (Medal) glues are in broad sheets of a good yellow color, and fairly thick. They are clearer than the Unbranded and Scotch and exhibit "fiber" to a greater degree. By "fiber" is meant not only the appearance of strength, since this is common to a great number of glues, domestic as well as foreign, which prove very weak on test, but rather a "waviness" in the texture that is an infallible index of strength, Certain forms of cutting apparatus faintly mark the surface of the dried glue with parallel lines, very close together. These must not be mistaken for "fiber." Just as the "grain" in wood indicates soundness as well as careful treatment, so the "fiber" in glue is indicative, not only of good stock, but proper treatment and cooking as well. The Sun and Medal glues average in test 1 1/2 and 1 1/4 respectively. A characteristic of these glues, worthy of notice, is that the viscosities of their solutions are not as low, proportionately to their jelly strengths, as those of the great number of foreign glues, although both of these glues are quite clear. It is evident, therefore, that this clearness has its origin in the preliminary treatment of the stock, rather than in processes aimed to remove by precipitation, the non-adhesive, viscous elements in the glue liquors. It has already been pointed out that such processes are too. radical, removing much that is available in the proper working of the glue.
Tancrede & Cie. produce a gelatine that is without exception the strongest that has come to the author's notice. It is in narrow sheets of medium thickness, of a pale yellow color in some lights and almost colorless in others. The test is two grades higher than A Extra and seldom varies. The jelly of a 25 per cent solution, while yellowish and not absolutely clear, is so tough that it is with difficulty pulled to pieces with the fingers. The melting-point of the jelly is rather too high for a culinary article. The solution is decidedly alkaline in reaction and its viscosity averages 35 seconds. The objection is made that this gelatine is in reality too strong for the average work. Despite its peculiar characteristics, it is a true gelatine, the addition of even a few drops of 40 per cent formaldehyde solution producing a change to a tough, elastic mass. In the matter of absorbing foreign odors, it is as sensitive as butter, and if stored for a short time in proximity of crude phenol will soon become impregnated with the permeating odor of the latter. This fact has led to the erroneous conjecture that the product itself is preserved by means of carbolic acid and hence manifestly unfit for culinary applications.
Italian Glues. - While comparatively little glue is produced in Italy, as compared with the output of other countries, the product is of excellent quality, and in many respects similar to the French, being typical of "gelatine-glue" to even a -greater degree than the latter product. Two concerns, the "Societa Agricola, etc.," in Milan, and the "Fabrici Torinese di Colla e Cocimo," in Sorrento, produce glues that are worthy of attention. The Societa glue is a cheap grade similar to the Colle sans Marque of Tancrede, testing about the same, but somewhat better adapted to sizing work. This corresponds, also, with certain of the weaker English glues, but is vastly superior to the low-grade German. The Fabrici produces gelatine-glues and gelatines, the former having their exact duplicates in the product of the Michigan Carbon Works, and the latter in the Silver Label, Bronze Label, and Gold Label gelatines of German manufacture. Like the German product, the Torinese high-grade gelatines are in the form of colorless, extremely thin, transparent sheets, testing from 1 1/2 to 1 X. The jellies are remarkably clear and of proper melting-point. Italian glues are a trifle higher in price than the corresponding French, as they are redipped after drying the first time, in order to improve the gloss or luster.
Russian Glue. From what has been said in regard to Russia as the originator of opaque or colored glues, it must not be inferred that opacity is achieved in exactly the same way as in this country. A consider-able quantity of Russian glue is made from bones, the dry product being in the form of brownish-white sheets. The bones are degreased by the usual method, and the customary treatment with hydrochloric acid resorted to, to deprive them of mineral constituents. The acid is permitted to act on the bones until they just become flexible, when the acid is drawn off. As a result of this incomplete treatment, phosphates remain in the cartilage and are incorporated with the finished product which thereby acquires a whitish color. The practice of adding mineral coloring matters to both hide and bone glues originated in the endeavor to imitate Russian glue. It is said that the addition of a small amount of coloring matter does not affect the tenacity of glue, but that an excess tends to weaken it. This does not accord with the contention of numerous consumers of opaque or colored glues that such product is stronger and dries quicker than the corresponding clear.
Some of the opaque or colored glues manufactured in various European countries are genuine Russian, prepared by the above process. Others, again, are made by the same methods as are in vogue in this country, namely, the addition to the glue liquors of various mineral coloring matters.