Reports on the chemical analyses of bacteriological bouillons and on a comparison of bacterial counts on whole and skimmed milk, separated and centrifuged cream, have been prepared.

With a view to improving the methods of vinegar production in the home from a wide variety of fruits, the acetic group of organisms has been studied, and, for the purpose of improving the production of soured foods, a study of the group of lactic organisms has also been conducted. A mass of data on the composition of silage has been gathered for the Office of Farm Management.

Studies upon the fermentation of the soy bean and the production of soy sauce have been in progress, and investigations begun upon sauerkraut production three years ago have been extended to include the pickling of numerous varieties of vegetables and fruits and the preservation of these vegetables by various forms of brining. Not only cabbage but potatoes, spinach, beets, string beans, sweet corn, and even peaches have been handled by this process in a satisfactory manner. In cooperation with the States Relations Service, Farmers' Bulletin 881," Preservation of Vegetables by Fermentation and Salting," has been issued.

DRUGS AND PHARMACOLOGY.

The results of a study of commercial viburnum barks and preparations, and of Karaya gum as a substitute for tragacanth are ready to be submitted for publication. Observations on the leaves of Eupatorium glutinosum, offered for entry as "Peruvian matico," have been made public. Examination of the root of Macrotomia cephalotes, offered as alkanet, has shown it to yield a coloring matter similar to that of alkanet, but present in larger amount. A paper on this subject is in press.

A study of the manufacture of arsphenamine and of the patent literature on the subject has been completed.

Results of investigations on the pharmacology of oil of chenopodium, on the action of an isomer of caffeine, on the distribution and elimination of zinc and tin in the body, on the action of tartrates, citrates, and oxalates, on the influence of diet on the toxicity of sodium tartrate, on the production of glycosuria by zinc salts, on the action of succinate and its hydroxy derivatives have been published.

OILS AND FATS.

In cooperation with the Bureau of Plant Industry, the oil yields of a large number of samples of peanuts of different varieties, grown in various localities, have been examined, and a report on the results prepared. A preliminary analysis of the results seems to indicate that there is very little relation between the volume, weight, and oil content of the nuts. Analyses of okra-seed oil, papaya-seed oil, cantaloup-seed oil, lemon-seed oil, areca fat, tea wax, sugar-cane wax, squash-seed oil, cob-nut oil, licania-seed oil, and the oil of Aleurites triloba have been completed. The results of an investigation on the oil of salmon as a method for the determination of the species in the canned product are in press.

INSECTICIDES.

An investigation of the decomposition of di-lead arsenate by water, the results of which have been published, has demonstrated how injury may take place when treated foliage is subjected to the frequent action of light rains, fog, and dew. In cooperation with the Bureau of Entomology, the action of pure arsenious oxid, arsenic oxid, dilead and basic lead arsenate, and calcium arsenate have been tested on various insects. A number of new calcium arsenates have been prepared and their chemical and physical properties investigated. Methods for preparing the two most promising-tri-calcium arsenate and calcium meta-arsenate on a manufacturing scale have been developed, and a patent covering methods for the commercial preparation of tri-calcium arsenate has been obtained. The results of an investigation to determine whether fruits sprayed with Bordeaux mixture may retain enough copper to be objectionable are in Irocess of preparation. A similar study has been made upon the retention of hydrocyanic acid in foodstuffs that have been treated with this gas for the purpose of destroying insects. The work on the poisoning of bees by sprays is to be published by the Bureau of Entomology. The efforts to modify the formula for Bordeaux mixture have progressed to such a point that it is possible to say that in all probability a formula which will contain much less copper than the present formula can be used for potatoes. The results obtained in the study of the adhering qualities of various copper and sulphur fungicides are to be published by the Bureau of Plant Industry. A report upon plants used as insecticides is in press.

ANALYTICAL METHODS.

There have been published methods for the separation of aluminum from iron by means of ether; for the preparation of heavy leathers for analysis; for measuring the absorption of paper; for the estimation of anthraquinone; for the detection of added color in butter and oleomargarine; for the determination of arsenates in insecticides by potassium iodate; for the estimation of fat in condensed milk and milk powders; for the detection of added water in milk by means of a simplified molecular concentration constant; for the analysis of acetylsalicylic acid and adulterants; and for the determination of the volatile oil content of citrus fruits.

There are in press papers upon the estimation of theobromin; of loosely-bound nitrogen as ammonia in eggs; of copper in insecticides; of copper and zinc in gelatin; and of vanillin and coumarin in factitious vanilla extracts. There are also in process of publication papers upon the evaluation of hexamethylene-tetramine tablets; upon the gravimetric and volumetric determination of zinc precipitated as zinc mercury thio-cyanate; upon the identification and determination of potassium guaiacol sulphonate; upon the separation and quantitative determination of the lower alkylamines in the presence of ammonia; and upon the application of the cryoscopic method for determining added water in milk.

Investigations have been completed upon the determination of acetic acid, methyl alcohol, and acetone in pyroligneous acid; upon the limits of sensitiveness of the United States Pharmacopoeia method

for the determination of lead in zinc oxid; upon a new method for the determination of caffeine of general applicability; upon the determination of saccharin; and on the determination by the Kjeldahl method of nitrogen in certain organic compounds.

The food or drug analyst frequently faces the difficult problem of identifying a substance isolated from complex mixtures in very minute amount and in no high degree of purity. This is especially true in the identification of active principles in the course of the analysis of medicines. The analysts in these cases depend either upon a physiological test or upon more or less vague color reactions. From time to time efforts have been made to introduce the use of the microscope in identifying crystalline materials. Inasmuch as the mere appearance of crystals is not necessarily characteristic, the use of the microscope has been of value only to a limited extent. In recent years methods have been developed for the exact measurement of very minute crystals and also for the determination of the optical properties of such minute crystals. These optical-crystallographic methods hitherto have been applied in the main only to inorganic substances, more especially in mineralogy. It would seem that the same methods might be applied with great advantage in food and drug analysis. Therefore work was undertaken to modify the methods of optical-crystallographic study, as applied to minerals, so as to render these methods applicable to the substances met with in the work of the bureau. Department Bulletin 679, "The Application of Optical Methods of Identification to Alkaloids and their Compounds," giving the results of this investigation, was published. Work is now in progress to apply these methods of identification to specific groups of substances, so that in time the optical-crystallographic properties of a large number of substances, the identification of which is required in the course of food and drug analyses, may be recorded. The work upon one such group, the cinchona alkaloids, has demonstrated that these methods are eminently suitable for identifying or distinguishing from one another these closely related bases. The results have been published.

Incidental to this work, a study has been made upon the possible value of optical properties in tracing the configurations of organic substances. Some interesting results have been obtained and made public. In certain simple cases it was found possible to work out space lattices for organic compounds from a consideration of their optical and crystallographic constants. A note on the fundamental polyhedron of the diamond lattice has been published.

COLLABORATION.

The Bureau of Chemistry has cooperated with the Post Office Department in helping to secure fraud orders against a number of concerns marketing through the mails preparations with fraudulent medicinal claims. A number of frauds emanating from Chicago were suppressed.

It has also done much work for the Department of Justice. The Tariff Board has been assisted in the compilation of data concerning imported chemicals and drugs.

Recommendations have been made to the Railroad Administration on the subject of standard refrigerator cars.

The Bureau of Markets has been assisted in its food survey project, the Bureau of Chemistry having handled the work in certain cities. The General Supply Committee has been assisted, especially with reference to paper specifications.

In cooperation with the Bureau of Biological Survey, studies have been made on the best methods of poisoning rats.

REF

REPORT OF THE CHIEF OF THE BUREAU OF SOILS.

UNITED STATES DEPARTMENT OF AGRICULTURE,
BUREAU OF SOILS,

Washington, D. C., September 11, 1918. SIR: I have the honor to transmit herewith a report covering the operations of the Bureau of Soils for the fiscal year ended June 30, 1918.

Respectfully,

Hon. D. F. HOUSTON,

Secretary of Agriculture.

MILTON WHITNEY,

Chief of Bureau.

SOIL SURVEY.

Notwithstanding a certain amount of interruption in the work of the soil survey, due to war-time conditions, a larger area of detailed mapping was done during the fiscal year 1918 than during the preceding year, the area covered amounting to 38.136 square miles.

Prior to this year a total of 445,825 square miles had been mapped, so that the total area covered by the detailed work of the survey at the close of June 30, 1918, was 483,961 square miles. That part of the United States lying within regions where the rainfall is sufficient for crop production or where water is available for irrigation covers approximately 1,750,000 square miles. The area mapped in detail during 1918 was equal to approximately 2.2 per cent of this area, the total mapped in detail to date to 27.6 per cent, and the total, both detail and reconnoissance, much of the latter area calling for no further work, to 54.3 per cent of it.

Reconnoissance soil mapping was carried on in California only in 1918, where an area of 4,735 square miles in the southern part of the State was covered.

Of the 38,136 square miles mapped in detail, all except 4.429 miles, distributed in five States, was done in active cooperation either with some State organization or with some of the bureaus of the United States Government. Four of the five States in which no cooperation was given cooperated in this work in former years but were obliged to drop it for the present on account of war conditions. In a few other States no work ... undertaken, owing to temporary inability of these States to continue active cooperation under existing conditions. At the close of the fiscal year active cooperation in soil-survey work was in operation with 22 States and with four bureaus of the Federal Government.

The statistical details of the work of the survey are shown in the accompanying tables.

Of the total area mapped in detail during the year, 11,936 square miles lay within the cotton belt, 4,410 square miles in the Pacific Coast States, and 21,790 square miles in the rest of the country.