摘要:

The effect of the moisture content of silk fibroin on the amount of weighting it takes up in given periods of time from a 30° Bé. stannic chloride solution has been determined. Saturated silk (> 35% moisture content) attains maximum adsorption much faster than does dry silk, whereas a minimum rate of adsorption exists for silk of about 10–23% moisture content. An explanation has been advanced for these phenomena based on the rate of swelling of silk in water and in stannic chloride solution, the size of the pores in dry silk and the effect that the water in these pores would have on the stannic chloride solution entering them. It is pointed out that the weighting taken up by silk from stannic chloride solutions is probably adsorbed not as stannic chloride but as a mixture of the various tin complexes which have been shown to exist in aqueous stannic chloride solutions. The effect on the weighting of increasing the temperature of the hydrolyzing bath and of the addition of inorganic chlorides and sulphates to this bath has also been investigated. The final weighting retained by the silk has been shown to consist of hydrated stannic oxide, the amount of water present depending upon the conditions obtaining during hydrolysis and drying.

ISSN:1923-4287    

DOI:10.1139/cjr37b-006

出版商:NRC Research Press    

年代:1937

数据来源: NRC

摘要:

A modification of Pregl's micromethod for the determination of sulphur in organic compounds has been found to be satisfactory and convenient when applied on a macro scale to wool.The investigation of various methods of cleaning the samples shows that the best results are obtained when the wool wax is extracted with a solvent before washing with water. It is shown that a treatment with dilute hydrochloric acid is not necessary in preparing the sample.Three different procedures have been followed in determining the dry weight of the sample and the differences in the results are discussed. Results obtained by the new method are compared with those obtained by other recognized methods, and the agreement with the results of the Benedict-Denis-Barritt method is shown to be very good.

ISSN:1923-4287    

DOI:10.1139/cjr37b-007

出版商:NRC Research Press    

年代:1937

数据来源: NRC

摘要:

The differential heat of adsorption of oxygen on activated cocoanut charcoal has been measured over the low concentration range to 14 micromoles per gram, by means of an improved ice calorimeter and a new charcoal bulb, in which oxygen is introduced into the middle of the charcoal mass. At zero concentration, a heat of adsorption of 129.0 kcal. per mole of oxygen was found, dropping to 72.0 kcal. at approximately 6.0 micromoles per gram. The initial heat of adsorption is much higher than the highest value that has been obtained previously. This indicates that the plain charcoal bulb previously used permitted loss of heat from the calorimeter; consequently, the values for the initial heats of adsorption were low. The theoretical significance of the high initial heat is discussed briefly.

ISSN:1923-4287    

DOI:10.1139/cjr37b-008

出版商:NRC Research Press    

年代:1937

数据来源: NRC

摘要:

The pretreatment of spruce wood in various neutral salt solutions was found to retard subsequent delignification in sulphite liquor to an extent depending upon the position of the ions of the salt in the lyotropic series. Increase in the salt concentration increased the effect of pretreatment.

ISSN:1923-4287    

DOI:10.1139/cjr37b-009

出版商:NRC Research Press    

年代:1937

数据来源: NRC

摘要:

The tap-roots ofCorydalis ochotensiswere found to contain a relatively large amount (10%) of an amino-acid, the chemical examination of which disclosed it to be the hitherto unknownmono-acetyl-d-ornithine. Although acyl and aroyl derivatives of amino-acids have long been recognized as animal catabolites, such derivatives do not appear to have been previously observed as plant anabolites.

ISSN:1923-4287    

DOI:10.1139/cjr37b-010

出版商:NRC Research Press    

年代:1937

数据来源: NRC