number of shipments objectionable because of worms or mold, a common condition not long ago. Greater care in drying and in shipment of chestnuts has cut down the number of objectionable importations. Less than 5 per cent of the shipments of walnuts and filberts were detained. The percentage of Brazil nuts and cashew nuts detained because of moldy or wormy conditions was about 15 per cent. Shipments of almonds showed little deterioration from these causes.

Medicinal preparations.—M a ny shipments of medicinal preparations are detained because of false therapeutic statements. The number of shipments of products considered to be grossly misbranded, in that they were represented as treatments for such serious diseases as cancer, tuberculosis, influenza, and diabetes, when in fact there was no basis for the statement, was unusually large. Some of these products were preliminary shipments from a firm specially organized to exploit the product in question. Other shipments would have followed but for the action taken.

FOOD STANDARDS

The food standards committee, formerly known as the joint committee on definitions and standards, is composed of three representatives from the United States Department of Agriculture, three from the Association of American Dairy, Food, and Drug Officials, and three from the Association of Official Agricultural Chemists. Two meetings only were held during the year.

A definition and standard were adopted for cultured skim milk, cultured buttermilk, and a new definition was adopted for rice. The definition for sweetened condensed milk was revised in order that the requirements for milk entering into its composition might correspond to those for milk as defined. The definitions and standards for alimentary pastes and macaroni products, including noodles, were revised and adopted.

Several hearings and conferences were held upon the subjects of cultured skim milk, so-called process cheese, cream meal, a product of corn, and so-called smoked salt.

Schedules were prepared for the consideration of the committee on purified middlings (farina) and semolina, and on a series of strained tomato products. After discussion, action upon the proposed definition and standard for ice cream was deferred.

Since the last report a number of the definitions and standards adopted by the department, upon the recommendations of this committee, have been adopted by State food-control officials. Their general acceptance of these standards is resulting in greater uniformity in regulation of the sale of food products throughout the country.

CERTIFICATION OF COAL-TAR COLORS

The extensive chemical and physiological tests to which all dyes offered for inclusion on the list of certified colors are subjected were concluded on a new green dye, offered as St. Louis green and finally accepted as fast green FCF. Feeding and toxicological experiments on this dye and on light green SF yellowish and Guinea green B, the two green dyes previously certified, showed that in general the fast green FCF and the light green SF yellowish are about on a par and are superior to Guinea green B by onehalf.

A report on the results obtained in the spectrophotometric study of the effect of the permitted coal-tar colors upon the hemoglobin of the blood has been prepared for publication. It was shown that these dyes, when mixed with defibrinated blood of cattle, cause the conversion of oxyhemoglobin to "reduced hemoglobin," a normal reaction. No evidence of methemoglobin, a danger signal, following the use of any dye on the permitted list could be detected.

Table 2 shows the quantities of food colors certified during the year, as compared with the quantities certified during the preceding four years.

TABLE 2.-Coal-tar food dyes certified,

Seven batches of straight dye, one repacked straight dye, one repacked mixture, and 26 mixtures were rejected.

Miscellaneous Circular 52, which gives the procedure for the certification of coal-tar food colors, has been revised and will be issued shortly as Service and Regulatory Announcements, Food and Drug No. 3.

FOOD-CONTROL INVESTIGATIONS

The enforcement of the food and drugs act each year calls for new and improved methods of analysis and examination to keep abreast of the new forms of adulteration which appear from time to time and to make it possible more efficiently to carry out the terms of the law. During the past fiscal year particular attention was given in the laboratory to the following products.

CEREAL PRODUCTS

Comparative analyses of farina and semolina indicated that farina has a higher water-soluble-nitrogen content precipitable by 40 per cent alcohol and lower ash, lipoid, and protein contents than semolina. Ratios of lipoids, ash, and protein to water-soluble nitrogen precipitable by 40 per cent alcohol may be of value in differentiating between the two products.

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Increasing the prepanary" fermentation period of strong gluten doughs, containing 3 per cent yeast and 3 per cent sugar, from one hour to one and three-fourths hours produced loaves having more elastic crumb, and in other respects equal to, if not superior to, those made with the shorter fermentation time.

Baking tests were made with different flours using a "fixed type" of procedure in which, with the exception of absorption, the flours were the only variables. The same flours were also baked using the ordinary procedure in which the formula is about the only constant. The former method showed more strikingly the baking qualities of the flours.

It was demonstrated that if raisins are first soaked in malt extract they will not char when exposed to the direct heat of the oven in baking a raisin loaf. This practice is used by commercial bakers.

In the analyses of whole wheat and graham flours certain data to be used in differentiating between wheat meal and a scalped product were obtained.

and

starch CaO The ratios of seemed bran MgO to indicate differences that might be considered diagnostic.

Commercial rye flours from Washington (D. C.) bakeries contained approximately the same amount of moisture as wheat flour.

A note on the influence of peptic digestion in the determination of total carbohydrates in cereal products was published in the Journal of the Association of Official Agricultural Chemists, volume 9, page 482 (November 15, 1926). It was found that permitting pepsin to act upon cereals prior to treatment with diastase greatly facilitates the conversion of starch.

The investigation of malted milk showed that no lipolysis occurs when a malt-flour infusion is permitted to act on neutral butterfat or dried whole milk. It was concluded also that with proper control of conditions with respect to temperature and hydrogenion concentration, a malt-flour infusion will cause digestion of milk protein. Regarding the preparation of malt-flour infusion itself, it was shown that: (1) A malt-flour infusion prepared at 65° C. has a hydrogen-ion concentration of about 5.7 and an acidity as lactic of approximately 0.14 per cent; (2) the mashing temperature does not materially affect the hydrogen-ion concentration; (3) the highest sugar degree is obtained at 55°; (4) the temperature of 55° does not permit of complete starch conversion in four hours, although by increasing it to 65° C. for one hour a maximum sugar degree is yielded.

CHEESE

The study of the effect of aging of cheese on the fat constants was completed. The results showed that the Reichert-Meissl number of the fat of Italian Pecorino cheese was lower and the Polenske number higher than those of the fat of cows' milk cheese and that aging produced a lowering of the Reichert-Meissl number. The Reichert-Meissl number of the fat of Roquefort cheese made from goats' milk was found to be abnormally low and the Polenske number higher as compared with the Reichert-Meissl and Polenske numbers of the fat from the goats' milk itself, but very little change took place upon aging with respect to these fat constants.

Satisfactory methods for the determination of added citric and tartaric acids as emulsifiers in process cheese were outlined.

Experiments on a pack of blanched and of unblanched string beans showed that in some cases it is possible to get a full can when using unblanched beans. This work, taken in connection with that previously done on unblanched beans, indicates that some unblanched beans will increase in cut-out weight over put-in, and that others will decrease, owing probably to differences in maturity, growing conditions, or variety.

Experiments to determine the effect of freezing and thawing on canned peas showed that, after being frozen, the skin of the peas is much tougher than the skin of the peas in similar cans held at room temperature. No other effects were noted in these experiments, which were, however, too limited to permit final conclusions.

CACAO PRODUCTS

A method for the estimation of milk protein in milk cacao products was devised and published in Industrial and Engineering Chemistry, volume 19, page 501 (April, 1927). Incidental to this study, a paper on the determination of casein in milk was published in the Journal of the Association of Official Agricultural Chemists, volume 10, page 259 (May, 1927).

FRUIT ACIDS

A paper on the application of the Stahre reaction to the accurate determination of citric acid published in the Journal of the Association of Official Agricultural Chemists, volume 10, page 264 (May 15, 1927), sets forth the conditions required for obtaining maximum yields of pentabrom acetone from citric acid. It shows that under

proper conditions as little as 4.5 milligrams of citric acid in the aliquot under examination yields acceptable results.

The further study of methods for the determination of fruit acids disclosed the fact that for very small quantities of tartaric acid (5 milligrams) the Kling method is not always reliable. It is believed that for determining such small quantities, the second precipitation should stand overnight in order to complete the reaction. Determinations of malic acid by the official method (Dunbar-Bacon procedure) are not satisfactory for small quantities of the acid and work for perfecting the method is now under

way.

BEVERAGE AND FLAVOR INVESTIGATIONS

Because of the enormous increase in the distribution of bottled cocoa and cocoa-milk beverages preserved with hydrogen peroxide, accurate and dependable methods for the determination of minute quantities of this chemical in such food products have been worked out and described to State officials and its efficiency as a preservative in such beverages investigated. Federal and many State officials hold that hydrogen peroxide is not a proper ingredient of beverages. Hydrogen peroxide persists for a long time in such beverages and prevents bacterial activity as long as determinable quantities remain. The results of these studies are reported in two papers, entitled "Persistence of hydrogen peroxide in cocoa-milk beverages" and Efficiency of hydrogen peroxide in preserving cocoa-milk beverages," to be printed in a trade journal. Through the studies on cocoa-milk beverages it was found that the powdered milk used was a serious source of contamination of the beverage. Consequently, samples of powdered milk from 39 manufacturers throughout the country have been procured and examined. The bacterial content of these samples varied from a few hundred to millions per gram. The organisms included nonspore-forming bacteria, resistant spores, and yeasts.

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Manufacturers of imitation-maple flavors maintain that their products are not imitations because no one has ever manufactured genuine maple flavor. To show that such a flavor can be made, a laboratory process was developed for concentrating the flavor in maple sap or maple sirup to such a

degree that when from 2 to 4 ounces of it is added to a gallon of sugar sirup of suitable density a reconstituted maple sirup is produced which has the same composition and properties as ordinary maple sirup. A public service patent for a flavor to be manufactured by this process from maple sap, maple sirup, or maple sugar has been applied for.

The practice of adding imitation maple flavor to figs has been uncovered. Suitable action to correct this practice, or to insure proper labeling, is under way.

Samples of known origin of Michigan cherry juices and cherries have been analyzed and the results sent to the field force of the bureau and to State officials, as an aid in interpreting the results obtained in the examination of commercial samples of cherry products alleged to contain cherry juice.

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The examination of 60 barrels of cold-pack" strawberries and 25 barrels of " cold-pack" cherries was completed. The content of fruit juice in the samples was accurately determined by obtaining refractive indices of the fresh fruits and of the fruit sirups after storage. The results were sent to Federal and State food officials throughout the country.

Commercial drug products alleged to be radioactive reach the laboratorv in many different states of physical condition, some as ores, some as clear liquids and opalescent liquids, and others as pills, pastes, etc. Methods for preparing these various kinds of samples for analysis of radium content have been developed and reported for publication.

DRUG-CONTROL INVESTIGATIONS

In cooperation with the Bureau of Home Economics, an extensive survey of cod-liver oils and cod-liver oil preparations found on the market was undertaken. Many products purporting to contain, in concentrated form, the active principles of cod-liver oil are offered for sale. Nearly all such preparations examined were either nearly or entirely lacking in vitamins. The truthful labeling of such products, not only as to composition but as to therapeutic representations, has received attention. Most of the oils so far examined, both domestic and imported, have been found to be of good quality. A close check is being maintained on imported cod-liver oils, for both human and animal use.

Results of a number of investigations on drug methods were published. These include researches on automatic devices for extracting plant material, the detection of diethyphthalate (an alcohol denaturant) in drug products, errors in the determination of alkaloids in the presence of soaps, suitability of chloroform for extracting alkaloids, the extraction of santonin in santonica, the stability of various alkaloids, such as atropine and hyoscyamine, during analysis, and methods for the examination of ipecac. Methods of examination of ginger and its various preparations, based on a study of its constituents, have been developed, also methods for determining cinchophen and podophyllum.

PHARMACOLOGICAL INVESTIGATIONS

The official bioassay standards specified in United States Pharmacopoeia, X, were distributed to 21 firms and analysts in this country and to official investigators in England, Canada, Belgium, and Spain. During the year 65 samples of drugs and 106 importations of crude ergot were assayed. Two articles upon the assay of ergot were published. It was found that samples of crude ergot coming directly from Spain or Portugal were usually as strong as, or stronger than, the physiological requirements outlined in the Pharmacopoeia, whereas those from Russia were usually below this standard physiological activity.

Experiments with the method of assaying mydriatics developed in the bureau have been extended to cover other mydriatics. The method has also been adapted to the quantitative assay of miotics. Information is now available upon atropine, hyoscyamine, hyoscine, homatropine, cocaine, pilocarpine, and physostigmine.

In connection with a case brought under the Federal food and drugs act, apples were seized on the ground that they contained excessive spray residue. Chemical analysis showed the presence of 0.05 grain of arsenic per pound, which corresponds to 0.25 grain of lead arsenate per pound. Peelings of these apples were fed to rabbits over a period of about seven days, after which the rabbits were killed and their tissues examined. Marked hyperemia and submucosal hemorrhages in the stomach walls, and congestion of the cortical and medullary layers of the kidneys were produced. Arsenic was found throughout the body; lead was localized in the bones. This case was

tried before a judge and jury, and verdict returned for the Government.

Experiments in which di-lead arsenate was fed to rabbits brought out the interesting fact that lead and arsenic may be transmitted through the mother's milk to nurslings.

An article on so-called habituation to arsenic, published in the Journal of Pharmacology and Experimental Therapeutics (vol. 28, p. 351, September, 1926), gives the results of a series of experiments which showed that there is no probability that any noteworthy systemic or gastrointestinal habituation to arsenic will be developed.

The study of the effects on health of food contaminated with tin was continued. Pumpkin and asparagus containing varying quantities of dissolved tin were fed to a "poison squad" of volunteers from the Bureau of Chemistry. Only small quantities of tin, or none, were found in the urines voided during the experimental period.

The histological examination of tissues of animals fed sulphur dioxide indicates that large doses cause definite injury and that small doses may cause some damage.

From the studies conducted this year it appears that the minimum lethal dose of gossypol, injected intraperitoneally into rats, is 25 milligrams per kilogram for acute death and 15 milligrams per kilogram for chronic toxicity.

The results of a three-year series of collaborative experiments with the Bureau of Biological Survey on the production of red-squill powders for use as rat poisons have been prepared for publication. This work suggests that white squill is not toxic to rats but that red squill is. The most toxic red-squill powders are usually those that have been dried at 80° C. Death from red squill is due to selective central respiratory paralysis. After extensive independent commercial study, a manufacturer in Ohio is now equipped to use about 1 ton of squill bulbs a day in the preparation of rat poison.

The use of thallium to eradicate various rodents, such as Zuni prairie dogs, coyotes, and porcupines is increasing. As the minimum lethal dose of this substance to white rats has been found to be 25 milligrams per kilogram, the possible danger to human beings in its use has been pointed out. It is as toxic as strychnine, and from five to ten times as toxic as

arsenious oxide when employed as a rat poison.

In collaboration with the Bureau of Biological Survey, some 20 substances that were believed to be of value as attractants or repellents to rats have been tested. Naphthalene was the only one which offered much hope. The work indicated that there is a possibility of developing a commercially feasible rat repellent containing naphthalene.

MICROBIOLOGICAL INVESTIGATIONS

To detect spoilage and to develop effective means of preserving foods bacteriological studies must be made. Special attention was given to canned goods, cheese, and fish.

CANNED FOODS

Because of difficulties in interpreting the bacteriological cause of spoilage in many samples of canned foods examined in the laboratory, a field laboratory was set up where bacteriological experiments were conducted with a view to ascertaining the types of organisms responsible for decomposition. During the summer string beans, corn, and Lima beans studied throughout the entire process of canning. The results on string beans showed that the most important source of organisms was the raw bean Beans as it came from the field.

were

growing on the upper portions of the vine contained more organisms than those growing next to or on the soil. From 500,000 to 3,000,000 organisms were found on the lower parts of the vine and approximately twice as many organisms were present on beans from the upper portions of the same vine.

Experimental packs of string beans, corn, and Lima beans were put up during the canning season with a view to causing flat sour decomposition under varying conditions. Examination of these goods has shown that the only typical flat sours produced were from cans held eight hours in the sealed cans before processing.

PREVENTION OF SUGAR DETERIORATION

The proposal to use certain volatile substances to prevent the deterioration of raw sugar was investigated. It was found that formaldehyde, acetone, chloroform, and carbon bisulphide destroyed the mold inoculated into the sugar under the experimental