Working prindples

Much of our previous argument has dealt with the situation where = Ml for an invariable magnitude jj,. In the observation of the relaxation of a flxed permanent dipole, it is necessary to work through many decades of frequency, up to 10 Hz or thereabout. If, on the other hand, MO oscillates at a frequency of 10 —10 Hz, the whole range of interest for relaxation is a fraction of this frequency, and is in prindple... 

The author has first endeavored to present in a dear, systematic way those fundamental prindples of structural and taxonomic botany which serve as a key to the approach of pharmacognic problems. But he has not been unmindful that the use of the work has extended to academic institutions and, so, in this edition, has broadened the scope of the former text. To this end about ninety additional pages of subject matter have been introduced. Several old cuts have been removed. Forty-three new ones have been inserted. Hypothetical discussions hav e been avoided which saves time for the reader. 

Prior to 1916, acetaldehyde was manufactured by the oxidation of alcohol in the liquid phase with bichromate and sulfuric add.1 Since that time it has been ade quite largely by the hydration of acetylene in sulfuric acid solutions activated with mercury salts. However, the relatively low price of ethanol in America has made the formation of acetaldehyde by vapor phase dehydrogenation or limited oxidation of the alcohol attractive commercially. To this end several methods have been proposed for conducting the transformation industrially. Developments of processes employing vapor phase oxidation reactions have all been based largely on the prindples disclosed by the early work, a considerable portion of which had been undertaken purely for the purpose of research and not industrialization. 

Personnel required to work in dean aseptic areas should be selected with care to ensure that they may be relied upon to observe the appropriate disdpline and are not subject to any chronic disease or condition which would present an abnormal microbiological hazard to the product. The same prindples should be applied to visitors to deanrooms. 

Elaborate and varied processes are required to sqiarate the maiqr components of plasms. Although a rational approach to the prindples of fractionation is now possible (see Part III), plasma is such a complex system that the steps of any successful process must be worked out largely by repeated trial, with gradual and systematic variation of the conditions of fractionation. Nevertheless, the motives for persistence in the undertaking are decisive. They fall into two classes (1) The superiority of purified plasma fractions to whole plasma for scientific study. (2) The superiority of the fractions to whole plasma for clinical and other uses (see Cohn, 35, 36, 37, 38). 

Beaumont studied the physiologic manifestation of digestion and produced a classic text on the subject in 1833. Despite his lack of training as a physiologist and his relatively unsophisticated medical background, Beaumont s work remained a model on the subject. In essence, by 1833, Beaumont had been able to outline the basic prindples of digestion in a human and establish the presence of hydrochloric acid in gastric juice. 

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