The Behavior of Benzidine toward Selenic and Telluric Acids

Within quite recent years, benzidine (p-diaminodiphenyl) has come into use as a precipitant for the sulfate ion. It was first applied as a quantitative reagent for the determination of sulfate by Raschig in 1903. Other investigators subsequently introduced modifications in the original method of Raschig and succeeded in obtaining very satisfactory analyses with this reagent. For example, in the analysis of water samples which contain iron salts, hydroxylamine hydrochloride is added to prevent oxidation of the benzidine. The precipitated benzidine sulfate is collected in the usual way and is either weighed direct or titrated with sodium hydroxide, using phenolphthalein as an indicator. Titration is rendered possible by the very weak basic properties of benzidine. Bruckmiller states that the benzidine method for sulfates in water compares favorably with the time-honored barium chloride method in point of accuracy, and has the advantage of being more rapid

Synthetic Hypnotics in the Barbituric Acid Series

The increasing demand for sleep-producing drugs is perhaps one of the characteristics of the restless age in which we now live. Not a year passes but half a dozen new synthetic hypnotics appear in the patent literature and a few of these find their way into the drug market. Most of these fail to meet the claims made by the manufacturers and are soon discarded, and the physicians continue to prescribe the eight or ten more or less familiar drugs that have survived several decades of clinical experience. Meanwhile, the chemical and pharmaceutical laboratories continue their search for the ideal hypnotic, for it must be admitted that none of the hypnotics in present day use are entirely free from certain objectionable qualities

Experiments with Soy Bean Meal as a Substitute in the Army Ration

The use of soy beans for human food has of late been the subject of a number of scientific investigations. The literature is not available to the writer at the present time, hence will not be discussed in this brief paper. The nutritive value of soy beans has, however, been established, and a future for this commodity as an article of human food is almost certain. The Chinese and Japanese have used soy beans for many years and prepared them in quite a variety of ways. In our own country little is known of soy beans except as a forage crop for cattle and swine

The occurance and significance of mannitol in silage

Mannitol, which may come into important industrial uses, particularly in the manufacture of explosives, is a normal constituent of corn silage and of silage made from other plants containing sucrose. Moreover, it occurs in sufficient amounts to suggest the possibility of its successful production from silage. These facts were brought out by the studies in silage fermentation carried on by the authors at the Iowa Agricultural Experiment station

Lactic Acid in Corn Silage

In a previous bulletin of this series a study of the volatile aliphatic acids of corn silage was reported in detail. It was shown that acetic and propionic acids are normally present in considerable amount, while higher members of the series, as butyric, seemed to impart undesirable qualities, and their presence might be taken as evidence of incipient spoiling. The total volatile acid recovered by distillation did not, however, in any case account for all of the acidity observed by direct titration of the original silage juice. The difference represents therefore non-volatile acid, which heretofore has been assumed to consist principally of lactic acid. Since the non-volatile acid, as determined by this indirect method, was in most of our samples in excess of the volatile acid, it was considered of sufficient importance to warrant further study

Amino Acid and Micro-Organisms

The study of amino acids has come to be recognized during recent years as a subject of tremendous importance, on account of its fundamental relation to the problems of human and animal nutrition. Not many years since, all proteins were thought to be of equal nutritive value. Now we know that many of the proteins are deficient in one or more amino acids, and cannot support life and growth unless supplemented by other proteins which make up the deficiency. And from a study of the proteins with reference to their amino acid make-up, the study of the amino acids themselves began to occupy the attention of chemists. Thus after the chemist had taken the protein molecule apart and identified the various amino acids of which it was composed, he undertook to synthesize these amino acids from simple substances, to separate the synthetic products into their optically active components, prepare numerous derivatives, and finally to study their behavior toward biological processes of both animal and vegetable nature

Volatile aliphatic acids of corn silage

1. Volatile aliphatic acids were found in considerable amount in all samples of good silage which we examined. 2. Acetic acid comprised about nine tenths of the total volatile acid present. 3. Propionic acid was next in importance to acetic. 4. Butyric acid was found in considerable amounts only in samples where some slight indications of spoiling were otherwise apparent. 5. Alcohols were found in appreciable quantities, but esters only in traces. 6. As far as volatile acids and alcohols are concerned, no differences were noted which could be attributed to differences in the type and construction of the silo

Synthesis of a Naphthotetrazine from Diethyl Succinylosuccinate and Dicyandiamide.

On account of the ease with which dicyandiamide can be prepared in quantity and at very small cost from the crude calcium cyanamide of commerce, this substance is beginning to find numerous applications in organic syntheses. Among other properties, the amidine structure of dicyandiamide has been taken advantage of for the preparation of certain nitrogen heterocycles. For example, by condensation with such substances as a-ketone acid esters, various pyrimidine derivatives are obtained. Thus, dicyandiamide condenses with amlonic ester derivatives and with acetoacetic ester to form substituted pyrimidines. It is not improbable that dicyandiamide is capable of entering into the same condensation reactions and yielding cyanamino derivatives or the various heterocycles now prepared from guanidine

A Comparison of Barbituric Acid, Thiobarbituric Acid and Malonylguanidine as Quantitative Precipitants for Furfural

All of the methods for the quantitative determination of pentoses and pentosans in agricultural products are based upon the conversion of pentose into furfural by distillation with a mineral acid, preferably hydrochloric, and subsequent estimation of furfural in the distillate by means of a suitable reagent. Günther, Chalmot and Tollens titrated the furfural with phenylhydrazine, using aniline acetate paper as an indicator. Stone made use of the same reaction, but used Fehling\u27s solution to determine the excess of phenylhydrazine. Later, Flint and Tollens showed that this titration method was not accurate, on account of the levulinic acid resulting from the decomposition of hexoses, as well as the instability of the standard phenylhydrazine acetate reagent used

The Protein Content and Microchemical Tests of the Seeds on Some Common Iowa Weeds

Weed seeds are recognized as an important factor in the dietary of our useful birds. Other things being equal, those seeds having the highest nutritive value might be expected to figure more prominently in this regard than seeds less nutritious. In animal feeding, the protein content of the feed is taken as the measure of its nutritive value, and the cost of the feed is determined largely by the protein content as ascertained in the chemical laboratory. Hence the protein content of weed seeds is of some economical importance as related both to the maintenance of our native birds and to the control of the weeds themselves