1890. | NEW YORK ACADEMY OF SCIENCES. 25 
of about 700 c.c. capacity containing some spirals of platinum 
wire; 25c.c. of potassium sulphide solution (containing 40 gms. 
per litre) are then added. ‘The Erlenmeyer flask is fitted with a 
Wiirtz tube, and this in turn connects with a common block-tin 
condenser. ‘To the drip end of the condenser is attached a tube 
bearing a bulb. The other end of this bulb tube dips under the 
surface of the liquid in the receiving flask. ‘This flask should 
contain the standard acid in amount from 25 to 50 c.c., as the 
case demands. I prefer'to use normal hydrochloric acid, but 
sulphuric acid may be used. 
Just before starting the distillation, from 50 to 100 c.c. of 
caustic soda (27 per cent) are cautiously run into the distilling 
flask and mixed with the contents, avoiding violent agitation. 
A piece of red litmus paper is now dropped in the flask, which 
is immediately stoppered. The litmus paper serves to show 
whether enough alkali has been added; if not, measure out 
10 c.c. more, uncork the flask, and introduce as before. Con- 
tinue these additions until the contents are alkaline; but avoid 
a large excess. When ready, heat up slowly to boiling, and keep 
up the distillation until at least 150 c.c. of distillate have passed 
over. Remove the receiving flask, and determine the acidity of 
the contents with 4; ammonia or 54, potassium hydrate, using 
methyl orange as indicator. 
A blank test should be made with the reagents, and under 
the same conditions as the original. Time of operation, two to 
two and one-half hours. 
Calculation of Results.—The number of cubic centimetres 
of acid neutralized by the distillate, calculated to nitrogen and 
multiplied by 6.25, is equivalent to the albumenoids, 7.e., glu- 
ten, etc. 
The determination of starch by the ordinary methods hitherto 
in vogue is uncertain and tedious. Irefer to inversion followed by 
use of Fehling solution and O’Sullivan’s diastase method, The 
first is unreliable, there being no certain method of ascertaining 
when all the starch has been converted into glucose; or the pro- 
cess may go too far, decomposing the starch to humic acid, etc.; 
result, low figures in both cases. 
The second is a more reliable method, but there is great diffi- 
culty in preparing the diastase, which does not keep. That pur- 
chased from dealers cannot be used. 
Von Asboth Process. 
This depends on the fact that starch unites with barium oxide 
to form a compound containing 19 per cent of barium oxide. 
