摘要:

A study was made of the preservative effect of various compounds in an 80% honey solution inoculated with a mixed culture of honey-fermenting yeasts. Sodium hypochlorite and chloramine-T preparations did not prevent fermentation in the highest concentration used (100 p.p.m. available chlorine). Hydrogen peroxide, though effective in a 0.5% concentration, exerted a marked bleaching action in addition to affecting the taste. Hexyl resorcinol completely inhibited fermentation in 0.01% concentration. Complete preservation was not attained with sodium salicylate within the limits permissible in foodstuffs, 0.06% being required. The sodium salts of boric, benzoic and sulphurous acid tested, all prevented fermentation within the limits. Sodium benzoate, sodium sulphite and sodium bisulphite were considered the most promising, and appeared to merit further testing on a practical scale for the prevention of honey fermentation.

ISSN:1923-4287    

DOI:10.1139/cjr30-045

出版商:NRC Research Press    

年代:1930

数据来源: NRC

摘要:

In these experiments, which are a continuation of work carried out in 1927 and 1928, certain aquatic animals were exposed to sunlight behind filters which transmitted different regions of the solar spectrum. The first filter transmitted both the visible and ultra-violet regions, the second the visible only and the third the ultra-violet only. Young eels,Anguilla rostrata, which are in shallow water when ascending the streams, an Amphipod,Gammarus locusta, which was taken from shallow tide-pools, and a Ctenophore,Bolinopsis infundibulum, which floats about at the surface of the sea, all proved to be very resistant to ultra-violet radiation, thus showing a marked contrast to those animals which remain at some considerable depth in the sea or which come to the surface only when the illumination is very weak, as the latter are killed in a short time by exposure to ultra-violet radiation.

ISSN:1923-4287    

DOI:10.1139/cjr30-046

出版商:NRC Research Press    

年代:1930

数据来源: NRC

摘要:

Uniform blocks of white pine wood were allowed to absorb water under various conditions of external and internal pressure, and in the presence and absence of air. The results shown graphically give some idea of the quantitative relation existing between penetration of water into wood and the various forces operating. It is concluded that the rate of penetration of water into an immersed block of coniferous heartwood is fixed by the rate at which the air in the block can dissolve and diffuse out.Applied to log sinkage, these findings show that under most conditions the limiting factor is the rate of escape of air from the log.

ISSN:1923-4287    

DOI:10.1139/cjr30-047

出版商:NRC Research Press    

年代:1930

数据来源: NRC

摘要:

The value of both filter paper and cotton batting as supporting media for blood while drying, prior to extraction of the blood cholesterol with chloroform, was examined; both were found to give unsatisfactory results. With each of these two absorbents the extraction was incomplete. A method is suggested for the determination of cholesterol in blood which involves the use of plaster of Paris as supporting medium, and extraction of the ground blood and plaster of Paris mixture with chloroform. The results obtained with this method are higher and more consistent than those obtained with either filter paper or cotton batting.

ISSN:1923-4287    

DOI:10.1139/cjr30-048

出版商:NRC Research Press    

年代:1930

数据来源: NRC

摘要:

Samples of cattle blood have been analysed and the concentrations of 10 constituents determined,i.e., cholesterol, sugar, non-protein nitrogen, urea nitrogen, amino-acid nitrogen, creatine, creatinine, calcium, inorganic phosphorus and chlorides. The normal range of each of these constituents was established. The diet fed to the cattle influences the cholesterol content markedly. Blood samples of cattle suffering from red water and some other pathological cases have been examined, and in each case the results show the variation of the contents of the various constituents.

ISSN:1923-4287    

DOI:10.1139/cjr30-049

出版商:NRC Research Press    

年代:1930

数据来源: NRC

摘要:

Analysis of the blood of cattle affected with Haematuria vesicalis shows its composition, with few exceptions, to be within the normal range. Two remedies have been found to have a beneficial effect upon cattle suffering from this disease; first, a change of drinking water from surface water to Artesian well water, second, the administration of ground coral rock. The surface water, the Artesian well water and the coral rock from the affected areas have been analysed, and from these analyses certain possible causes for the improvement above noted have been drawn; further field experiments are outlined to test these suggestions.

ISSN:1923-4287    

DOI:10.1139/cjr30-050

出版商:NRC Research Press    

年代:1930

数据来源: NRC

摘要:

Glycol-lignin at temperatures below 0 °C., dissolves completely in a mixture of four parts of acetic anhydride and one part of fuming nitric acid, giving rise to a 125% yield of a product (nitrated-lignin) which has undergone nitration and acetylation. The nitrogen in the product is present partly in the form of a nitro group, an ester of nitric acid, a nitroso compound and in another form not yet determined. A further treatment of this nitrated-lignin with a nitrating liquor of the same composition, followed by heating at 80 °C. causes a short initial oxidation, and yields a substance differing slightly from the first and having a C:H ratio almost 1:1. Repetition of the treatment does not seem to alter the percentage composition appreciably, until after the fourth treatment.Nitrated-lignin can be methylated, the methoxyl content of the product being more than double that of the original nitrated-lignin. It can also be reduced, the resulting product diazotized and coupled with β-naphthol disulphonic acid.The soluble products of the nitration reaction contain an acidic component which has not been identified.

ISSN:1923-4287    

DOI:10.1139/cjr30-051

出版商:NRC Research Press    

年代:1930

数据来源: NRC

摘要:

Quantitative measurements have been made, for the first time, of the rate at which liquids penetrate into wood in terms of the velocity normal to the wood-liquid interface. The effects upon this rate, of species, previous history, structure, orientation, thickness, nature of liquid, pressure head, temperature and time have been examined and measured. It has been found that wood behaves largely in a reversible manner provided the treatment does not alter its structure. A technique has been devised for maintaining a single chip in an unvarying environment and following the progress of the cooking process by the variation of the rate of flow of the cooking liquor through the specimen. An attempt is made to examine flow m wood from the standpoint of hydraulics, and a structure is suggested which agrees well with existing anatomical information and gives values for resistance to flow which compare favorably with experiment.

ISSN:1923-4287    

DOI:10.1139/cjr30-052

出版商:NRC Research Press    

年代:1930

数据来源: NRC

摘要:

Experiments have been carried out in which the energy losses of electrons striking mercury atoms have been studied. The apparatus was so designed that scattering relations could be studied for elastic and inelastic collisions.Energy losses representing the 4.7 or 4.9-volt energy level, the 6.7-volt energy level, the 10.4-volt level, or ionization, and some indication of intermediate levels have been found. Energy losses greater than the ionization potential have also been found at 11.5 and about 13.5 volts. The latter is without doubt the result of two successive collisions each resulting in the loss of 6.7 volts energy. The former due to its intensity cannot be explained as the result of two successive collisions, and its significance is discussed. Similar experiments by Whitney and Foard are discussed.The scattering curves are not as accurate as could be wished, due to an insufficient number of observations having been taken. They show, however, that the scattering is not of the type of the inverse square law of force. This is in agreement with observations by Arnot.

ISSN:1923-4287    

DOI:10.1139/cjr30-053

出版商:NRC Research Press    

年代:1930

数据来源: NRC