CIENCE 
Frmay, NoveMBer 22, 1918 
CONTENTS 
The Physical Chemistry of Bread: LIEUTENANT 
E. J. CoHN AND Proressor L. J. HENDER- 
BEI ee clotate tot stare Whee tate's cle v. ots elelvle Geibisiete miele 501 
Industrial Research and National Welfare: 
Re Ma ROBAE, 1), EVATIIC (35s iv 4) cpa eicuin ole DBs abe 505 
George Schrader Mathers: Dr. Lupvie HEK- 
BEGET Aoreds ci oP oom aie, Setctaitia la hevena. Ola Roe eieeane ete 507 
PRP EOURAS 2 MEO LINY, «0. oe 05 1d) py laid choi s 0 aisfopminree ale ot 508 
Scientific Events :— 
The Bequests of Mrs. Sage; International 
Scientific Organization; The Harvey So- 
ciety ; The American Society of Naturalists; 
The Baltimore Meetings of the Section of 
Zoology of the American Association for the 
Advancement of Science ........:.....--. 508 
Scientific Notes and News ............0000: 512 
University and Educational News .......... 513 
Discussion and Correspondence :— 
Botany after the War: PRoressor BRADLEY 
Moore Davis. A Possible New Fungicide 
for Wheat and Barley Smut: W. W. Mackie. 
Scientific Books :— 
Harshberger’s Text-book of Mycology and 
Plant Pathology: J. J. TAUBENHAUS ...... 516 
The Royal College of Physicians ........... 517 
Special Articles :— 
Suggestions regarding the Causes of Bioelec- 
tric Phenomena: Dr. L. H. HyMAN ...... 518 
The American Mathematical Society: Pro- 
PRRSBOR LES IN COLER ror nde p4sis,cisia'e:e es ss 0 524 
MSS. intended for publication and books, etc., intended for 
review should be sent to The Editor of Science, Garrison-on- 
Hudson, N. Y. 
THE PHYSICAL CHEMISTRY OF 
BREAD MAKING! 
THE art of making leavened bread has been 
so long perfected that the experience upon 
which present practise rests is now forgotten. 
Meanwhile the science of bread making, in- 
yolying physical, chemical and physiological 
problems of a certain complexity, and only 
recently promoted by a great organized in- 
dustry, has hardly kept pace with the ad- 
vance of biological chemistry. But at length 
war time necesssity has imposed new condi- 
tions, and the use of flours other than wheat 
has brought about changes from the best prac- 
tise of the past. 
It seems desirable, therefore, to review the 
physical and chemical processes involved in 
the fermentation of dough and the baking of 
bread, and make suggestions which may facil- 
itate the use of wheat substitutes. 
GLUTEN 
When wheat flour is made into dough the 
proteins, after absorbing water, hold together 
to a much greater extent than do the proteins 
of any other grain. This pruperty makes it 
possible to separate from the other constitu- 
tents of wheat flour the two proteins, gliadin 
and glutenin,? which are insoluble in water. 
The material which can in this way be washed 
free contains about ten per cent. of the flour® 
and includes about nine tenths of all the pro- 
tein material. It is called gluten. 
1From the Wolcott Gibbs Memorial Laboratory 
of Harvard University, in collaboration with the 
Division of Food and Nutrition, Medical Depart- 
ment, U. S. Army. 
2 Osborn, T. B., ‘‘The Proteins of the Wheat 
Kernel.’’ Washington, 1907. 
sBulletin 13, part 9, Division of Chemistry, 
United States Department of Agriculture. 
4 Jago, William, ‘‘Science and Art of Bread-ma- 
king,’’ pp. 288-303, London, 1895. 
