136 
CHEMISTRY: K. G. FALK 
at the center. Attention is thus called to the difficulty of securing re- 
producible values of the wavelength for such lines when the spectro- 
graph sKt is placed parallel to the axis of the arc, especially if an astig- 
matic spectrograph is used. With the sHt at right angles to the arc at 
its middle point, on the other hand, it is easy to obtain reproducible 
results* 
Our conclusions may be summarized as follows: 
1. It has been shown that the wavelengths of many lines in the iron 
arc spectrum depend upon the portion of the source used. 
2. These variations in wavelength appear not to be due to a general 
increase in pressure in the vicinty of the negative pole, but the ques- 
tions of a local increase in pressure and the possible effect of density 
are still under investigation. 
3. The energy distribution in the arc has been shown for two types 
of lines. 
4. Some working conditions whose observance favors the obtaining 
of reproducible values of wavelength have been quantitatively de- 
termined. 
AN EXPERIMENTAL STUDY OF LIPOLYTIC ACTIONS 
By K. George Falk 
HARRIMAN RESEARCH LABORATORY. ROOSEVELT HOSPITAL. NEW YORK 
Presented to the Academy December 31, 19! 4 
Purpose of this Investigation. The chemical changes which occur in 
animal and vegetable growth have focused attention in recent years 
upon a group of catalytic agents, the enzymes, which are capable of ac- 
celerating these changes. The study of the chemical nature and behavior 
of enzymes is, however, extremely difficult because of the complexity 
of the substances which occur in living matter and which constitute in 
most cases the material upon which the enzymes act. Thus most enzy- 
matic reactions involve changes in substances such as proteins or starches, 
which are themselves of imknown chemical structure. There are, how- 
ever, some which produce changes in simpler substances. Among these 
are the lipases, or the ester-hydrolyzing (including the fat-hydrolyzing) 
enzymes. In this case the composition and structure of the initial and 
final substances involved in the reaction are definitely known, and the 
uncertain factors due to the chemical nature of the substance acted upon 
are eliminated. 
