Cocoa-red, the coloring matter of the bean, seems to be related to the tannin or astringent principle also present, but authorities differ as to whether it is a decomposition product of a tannin, or whether a tannin is the result of its decomposition.

Small percentages of a gum and of tartaric acid have been reported. The aroma of cocoa is considered to be due to the presence of minute quantities of an aromatic volatile oil.

The preparations of cocoa are so numerous that more or less confusion of terms naturally arises. Most American manufacturers prepare a plain chocolate (known in Europe as cacao-masse), made by reducing the roasted and husked beans to a paste and pressing into form of cakes. When this is combined with much or little sugar (generally much), vanilla, and spices, the various "sweet," "vanilla sweet," "vanilla, "spiced," etc., chocolates are produced. These are also usually met in the form of cakes, but are sometimes pulverized and sold as "powdered " chocolates. The high percentage of fat renders a permanent powder impossible without its partial removal or the addition of some diluent, as sugar, starch, or flour. The preparations in powder known as "cocoas," "bromas," etc., are prepared in accordance with one or the other, or a combination of these methods.

Cocoa husks are offered on the market in bulk and in packages, but their use seems to be quite limited at present.

Perhaps no food material offers conditions so favorable for profitable adulteration and so well utilized by its manufacturers as do cocoa preparations. There is probably no more misleading or more abused term in the English language than "soluble cocoa." No cocoa in the market contains more than 10 per cent to 30 per cent of matter soluble in water unless the material so dissolved is foreign soluble material that has been added during the process of preparation. The term seems to be used to denote a preparation that allows none of the insoluble matter to deposit from the beverage prepared from it. This purpose may be accomplished in two ways; the material may be so finely divided that a very long time will be required for its deposition, or foreign substances (as starch or sugar) may be added to render the liquid of so high specific gravity or so pasty that the insoluble matter will not deposit. The first method is decidedly to be preferred; it accomplishes the object in view and puts the preparation in better condition for the action of the digestive juices, and all this without the addition of a cheap diluent that is always at hand in every kitchen should its use be desired. Any additions of this kind should be considered adulteration unless their nature and quantity are accurately stated.

Attempts at the preparation of easily "digestible cocoas" (preparations to which pepsin or other digestive ferments have been added do not come in question here, since the favorable condition of the preparation is not involved, but the supplying of a deficiency in the strength of the digestive juices) seem to fail in purpose and to be attended with the introduction of objectionable substances. The use of alkalis for this purpose is quite generally regarded as injurious to health, and the effect is the opposite of that desired.

The removal of the fat is not considered an adulteration when it is acknowledged, and it is undoubtedly desirable for persons with weak digestion. It seems important, however, that the public have a means of knowing accurately to what extent it has been removed. It also seems desirable that the percentage of sugar be accurately stated. The adulterants added are reported to be, besides starches and sugar, substances of organic and inorganic origin to increase the weight and

bulk, ferruginous and other pigments to restore the color of highly diluted preparations, and foreign fats to restore the normal percentage of fat, or to give the preparation the plasticity required for molding. The husk, because of its coarse nature and consequent tendency to act as an irritating substance in the alimentary canal, and in consequence of its poverty in the constituents that render cocoa valuable, is regarded as an adulterant when not removed, or when added to increase the weight or bulk of the preparation.

Sixty-two samples of cocoa preparations have been submitted to microscopical and chemical examination in the laboratory of the Department of Agriculture. A brief summary of the results of these investigations is presented in the following table:

For further details concerning the adulterations of tea, coffee, and chocolate, reference is made to Bulletin 13 of the Division of Chemis try, part VII (in press), which contains the full work of which the foregoing is a brief extract.

REPORT OF THE CHIEF OF THE DIVISION OF FORESTRY,

SIR: I have the honor to submit my sixth annual report upon the work of the Division of Forestry, together with a discussion of a few subjects of general interest which occupied the attention of the division during the year 1891.

Very respectfully,

Hon. J. M. RUSK,

B. E. FERNOW,

Chief.

Secretary.

INTRODUCTORY,

The past year has witnessed greater activity and interest in forestry matters than any previous one, due especially to the enactment of a law by Congress authorizing the President to set aside public timber lands for permanent forest reservations, and perhaps due also to an increase in the diffusion of information as to the practical importance and meaning of forest management. This better and more general appreciation of the objects and methods of forestry may, in part at least, be traced to the activity of this division, and more directly to the comparatively wide distribution of Bulletin No. 5, entitled "What is Forestry?" of which 25,000 copies were sent out to farmers, lumbermen, and others interested in forestry matters.

In this bulletin it was shown that the forestry interests of this country rank second, if not first, in the value of our annual products reaching the market, rivaling our agricultural production, and leaving far behind in value of product any single manufacture and many important interests or manufactures combined. The principles which underlie proper management of forest resources and those which apply to successful forest planting in the prairies are also outlined in this publication. The largest share of the expenditure of funds as well as of the attention devoted to any particular work has been bestowed upon investigations into the character of our timber trees, which were discussed more in detail in my last report under the caption of "Timber Tests." This caption, however, does not fully indicate the exact nature of the work in hand. While the testing of the timbers appears as the most conspicuous part of the work, and the more careful determination of average values expressing the strength of our wood materials is looked for with eagerness by architects, builders, engineeers, and consumers of wood, these features constitute in reality the smaller part and by no means the ultimate object of the undertaking. This object is a twofold one, namely, first, to find out in what relation the mechanical properties of timber stand to its structure and physical conditions, and thereby to find for

practice means of judging mechanical properties from a simple microscopic or macroscopic examination; and, secondly, to find out in what relation structure, physical conditions, and mechanical properties stand to the conditions under which the tree is grown, and thereby to obtain knowledge for the forest-grower as to the kinds of timber which will yield the best results in given soil and climatic conditions.

Forestry is by no means satisfied with the growing of trees, but is concerned also with the production of material of given quality. In the virgin forests species are found growing in widely varying conditions and hence of widely varying quality, but it can not be the object of forest management to follow nature in this particular. It must also determine under what conditions the best or the most serviceable quality of a given species is produced, and must encourage the production of the species under such conditions alone.

During the year there have been collected in the manner described, partly tested, and examined, 22 trees of white pine from Wisconsin, 23 trees of longleaf pine (P. palustris), 10 trees of shortleaf pine (P. echinata), 15 trees of loblolly pine (P. Tada), and 59 trees of various species of oak from Alabama. Besides, there were collected and partly tested and examined for the purpose of determining the influence of tapping for turpentine upon the quality of longleaf pine, 8 trees "boxed" and abandoned for five years, and 11 trees boxed and just abandoned; or altogether 149 trees, furnishing not less than 3,000 to 4,000 test and examination pieces. In addition, a series of tests to determine the influence of different degrees and methods of seasoning has been inaugurated.

So far this large amount of work has been possible under the always scantily measured appropriations for this division only through the courtesy of railroad companies in transporting test material free of charge; through the energy of Prof. J. B. Johnson in supplying all the needed testing apparatus, including a large beam and column testing machine, and in organizing the test work; and through the zeal and economical work of Dr. Charles Mohr and Mr. Filibert Roth in collecting and examining the material. To carry on this work expeditiously and most economically, an expenditure of not less than $40,000 per year should be allowed, this amount being based on the assumption that one competent man should be employed at the testing machines all the year. In three or four years data would thus be accumulated sufficient to employ for some time to come competent workers, who are to elaborate the laws of relation-the ultimate object of the undertaking.

A preliminary bulletin on this work in timber physics is now ready for the press, and will presumably be published before this report reaches the public, giving a historical review of similar work attempted before. and describing in detail the character of the present work, the methods and machinery used in testing, with illustrations, and the manner in which the physical examination is carried on.

If appropriations permit, it is planned to publish results three or four times in the year, in order to bring them as quickly as possible into the hands of those who need the data for practical application.

That there is a widespread and deep interest in this work, unique in the annals of this country, and almost in the world (the Prussian Government having just started out on a similar plan), is manifested by the reprint in full in many technical journals of Circular 7, describing briefly the methods pursued, and also by a large number of letters received by the Department from leading engineers, architects, lumbermen, and scientific societies, expressing appreciation, and pointing out

the great need of rapid progress of a work which will save millions of expenditure and direct and indirect losses which the country suffers from our ignorance as to the true values and strength of our building timbers. I may be allowed to quote from one of the many letters a striking passage, which opens the vista of the benefits to be derived, and also emphasizes the fact that our present knowledge in this direction is a "state of ignorance." Mr. D. H. Burnham, engineer of construction for the World's Columbian Exposition, writes: "When I was appointed engineer of construction, World's Columbian Exposition, August 1, I found it necessary to make changes in most of the buildings because I did not dare to use as high unit stress in timber as was used by my predecessor, although he claimed to be perfectly safe in his strains, and brought forward authorities-Trautwine and others-to prove his statements."

In connection with this work it became desirable to study, from a mercantile point of view, the lumber pines of the Southern States, which are taking a more and more prominent place among our building materials. It was found that such misconceptions existed among lumber-dealers, architects, and engineers regarding these pines, and their names as well as character, as to make it not an easy task to unravel the existing confusion. The result of these studies is given farther on in this report, and will, it is hoped, afford more light upon the subject of the pine lumber supply of the South than has hitherto been accessible. The revision of both the botanical and the common names of our arborescent flora, a work in special charge of the botanist of the division, has progressed during the year until it is nearly completed and will soon be ready for publication. Owing to the many other duties of office routine which must be attended to, all such work must necessarily progress slowly. Meanwhile the study material in the herbarium, wood collection, seed collection, bud collection, and bibliography is growing constantly; and correspondence, asking for advice in the most widely different fields, is increasing daily, consuming so much time of the divisional force that a large accumulation of valuable manuscript remains unpublished for lack of opportunity to prepare it editorially for the press.

SEED DISTRIBUTION.

The distribution of tree seeds for 1891 was made up of two disbursements: 100 pounds to forty State experiment stations and 300 pounds to general applicants. To the first, 300 packages of nine important conifers, varying in quantity per package from 2 ounces to 1 pound, were distributed, with letters of advice and directions as to the best method of handling seed received and reporting results. A general disposition to coöperate in this work has been expressed by nearly all directors of experiment stations, and also a desire to receive material so assigned in future, and a willingness to report upon the success of experiments with the same.

To about 400 general applicants-ranging over forty-nine States and Territories-were distributed a total number of 5,000 packages of tree seeds, including twenty species of important conifers and deciduous trees. According to the locality, each applicant has received from twelve to fifteen packages, each containing from half an ounce to 2 ounces of seed.

In addition to the above, five hundred 2-ounce packages of Acacia decurrens (Australian tanbark wattle) has been lately distributed to a AG 91-13