342 Proceedings of the Royal Society of Edinburgh. [Sess. 
XX. — On the Determination of Small Degrees of Enzymatic 
Peptolysis. By Dorothy Court, B.Sc., Carnegie Research Scholar, 
Mycology Department, Heriot-Watt College. Communicated by 
Dr E. Westergaard. 
(MS. received December 31, 1910. Read February 20, 1911.) 
In studying the conditions under which enzymes are produced in seeds at 
the beginning of germination, two main difficulties have been encountered. 
The one has been in devising means of maintaining sterility in the material 
without at the same time interfering with the formation and action of 
enzymes. Some experiments have been carried out with the object of 
determining the relative efficiency of some of the more commonly used 
antiseptics, but, at present, these are not sufficiently far advanced to admit 
of any general conclusions being drawn. They have, however, shown that 
saturation with chloroform ensures sterility under the conditions of the 
experiments which form the subject of this paper. The other difficulty 
has been in demonstrating small degrees of enzymatic activity. It is with 
this latter question I wish to deal here. 
In the present research, attention has been mostly confined to the 
activation of the proteolytic and peptolytic enzymes of the seed. The 
presence of traces of such in resting seeds of several plants has been shown 
by Vines ( Annals of Botany, vol. xxii.), Miss J. White ( Proc . Roy. Soc., B 
550), and others, and it has been further demonstrated in a large number 
of cases that the enzymatic activity rapidly increases during germination. 
For the purposes of this investigation it was accordingly necessary to 
devise a method whereby even slight differences in the enzymatic activity 
might be accurately determined. The usual methods of detecting and 
measuring proteolysis and peptolysis are only of service where the degree 
of activity is relatively high. The method of Kjeldahl and Weis, in which 
the enzymatic preparation is digested with a protein substrate and the 
increase in non-precipitable nitrogen estimated after digestion, is unsuitable 
for this reason, and also since it is too long and complicated to allow of 
many estimations being carried out simultaneously. Sorensen’s method of 
estimating peptolysis, in which the material is treated with formol and 
then titrated against standard alkali, is also unsuitable, since in dealing with 
substances of entirely unknown chemical constitution such as ground-up 
