CHEMISTRY: K. G. FALK 
557 
yellow light is a striking feature for each of the objects mentioned. 
Quantitative measures of intensity have not yet been made, but there 
is every reason to believe that the nebular condensations will reveal 
negative color indices of large amount. The knots of nebulosity are 
certainly bluer than the bluest of the neighboring stars, and one is 
reminded of the great photographic activity of the central star in the 
Ring Nebula in Lyra. 
Whatever the spectral character of these outlying regions may prove 
eventually to be, it must differ from that of the central nucleus, for the 
three central nuclei and the secondary nucleus at the end of one of the 
branches of M 51 are all much stronger in yellow light than in blue. 
Here the color seems to be in accordance with the typical absorption 
spectrum found in all similar objects thus far observed. 
It is still too early for any general conclusion, but preliminary photo- 
graphs of other spirals suggest similar results; and it seems not unlikely 
that the phenomena described are typical of this class of objects. 
In contrast to the spirals it is of interest to note the results for the 
bright planetary N.G.C. 3242, which is also illustrated. In this in- 
stance no important differences are revealed by the blue and yellow 
exposures, at least none which cannot be accounted for by possible 
differences in gradation on the two kinds of plates. 
1 Newcomb-Engelmann, Populdre Astronomie, Fiinfte Auflage, p. 672, Leipzig, 1914. 
2 These Proceedings, 1, 590 (1915). 
2 An isochromatic plate exposed behind a yellow filter. 
^Asiroph. J., 9, 133 (1899). 
Uhid., 21, 389 (1905). 
®An unpublished result obtained in 1909. 
THE ACTION OF ALKALI IN THE PRODUCTION OF 
LIPOLYTICALLY ACTIVE PROTEIN 
By K. George Falk 
HARRIMAN RESEARCH LABORATORY, ROOSEVELT HOSPITAL, NEW YORK 
Received by the Academy, August 22, 1916 
Introduction. — A summary of an extended experimental study of the 
lipolytic or ester-hydrolyzing enzymes was presented in these Pro- 
ceedings last year.i The changes in the lipases themselves under 
various conditions were the main objects of the investigation at that 
time, as a preliminary to the possible elucidation of the chemical struc- 
ture of the active groupings. The investigation of the factors which 
control the loss or destruction of this enzymatic hydrolyzing activity 
