S. Okada Bal 
SUMMARY. 
The use of methyl or ethyl alcohol as a precipitant for proteins 
in the determination of non-protein nitrogen or amino-acid ni- 
trogen in blood is undesirable. 
The methods of Greenwald and of Bock have been found serv- 
iceable for amino-acid nitrogen determination, but the procedures 
are somewhat troublesome. 
A method is proposed (the heat- dolih method) which has been 
found accurate, less troublesome, saving in time, and economical. 
In conclusion I wish to acknowledge my indebtedness to Pro- 
fessor T. Aoyama for his generosity in allowing me to carry out 
this work in his laboratory and for his encouragement. 
