ABSTRACTS OF TECHNICAL ARTICLES 131 



oscillators of around 100 megacycles and shows both theoretically and experi- 

 mentally that the highest stability found by many is only the result of for- 

 tuitous circuit adjustment that may readily lead to the desired result in this 

 frequency range. It is shown that the factor next in importance in producing 

 frequency stability is a low ratio of inductance to capacitance in the fre- 

 quency-determming circuit. It is also shown that a high Q contributes 

 little directly to stability. A high Q is necessar>' with low L/C ratios to get 

 oscillations but an improvement in Q alone may give poorer stability. To 

 get the fullest measure of stability with low L/C and high Q calls for slight 

 adjustments in the circuit and possibly the provision of loose coupling to the 

 frequency-determining circuit. 



Modern Spedrochemical Analysis.^ Edwin K. Jaycox. The spectro- 

 graph, originally developed by the physicist, has become a most useful tool 

 in the hands of the analytical chemist. Today few large analytical labora- 

 tories are without one. The instrument, with its attendant accessories, 

 provides a rapid method for analyzing metals, alloys, minerals, ores, liquids, 

 and gases, particularly for their metallic constituents and in some cases for 

 their anions. Both emission and absorption spectra are important to the 

 analyst. Important applications of the spectrograph to the analytical 

 problems of research and industrial organizations are discussed. 



The spectrograph did not come into general use as an analytical tool until 

 the early 1920's, although Kirchhof and Bunsen saw the practicability of the 

 method in 1860, when they published their paper entitled, "Chemical Anal- 

 ysis by Means of Spectral Observations." During the intervening years 

 only a few enthusiasts like Lockyer, Roberts, Hartley, Leonard, Pollack, 

 and de Gramont, kept the art alive. In spite of their persistent efforts to 

 influence chemists to use spectrographic methods, they were quite generally 

 ridiculed and the value of the method was recognized by only a few workers. 



In 1922, Meggers, Kiess, and Stimson published their paper "Practical 

 Spectrographic Analysis" and modern spectrochemical analysis was born. 

 Under the stimulus of this paper and the backing of a high caliber scientific 

 organization like the Bureau of Standards, the use of the spectrograph as an 

 analytical tool increased rapidly. This is evidenced from the Index to the 

 Literature on Spectrochemical Analysis by Meggers and Scribner. In 1920, 

 for example, only five papers were published concerning spectrochemical 

 analysis, four of which were by de Gramont; whereas in 1930, 33 papers 

 were published and in 1939, 170 papers, indicating an increasing interest in 

 and use of spectrochemical analysis in industrial and research organizations. 



^Jour. Applied Physics, December 1943. 



