1922] ATWOOD—FORM ALDEHYDE 245 
ing formaldehyde and two controls, and the iodine test applied 
and results evaluated. Figs. 7 and 8 show that although digestion 
is markedly checked by 1-40 formaldehyde at the end of the first 
one and a quarter hours, digestion proceeds with further intervals 
of time, so that by three hours the digestion which had been com- 
DIASTASE 
SERIES 
i 
eel 
Fic. 8.—Time factor as —— to starch digestion i in presence of formaldehyde 
mixed 1-320 parts water: 
(all conditions shown in du plicate); 1cc. 0.5 per cent solution Merck’s diastase, 
10 Cc. 25 per cent soluble starch solution, and 4 cc. formaldehyde used in tests (7), 
and a like amount of water in — (C); time periods in hours tests 1 to 5 respec- 
tively, 1.25, 1.5, 1.75, 2, 2.5 hou 
plete in the controls in half that time, has also occurred in the 
presence of the formaldehyde. The series in the presence of 1-320 
(fig. 8) formaldehyde was not so striking, but nevertheless shows 
satisfactorily that formaldehyde does not entirely inhibit the action 
of diastase, but retards the same. Turning to the effects on the 
starch digestion in living wheat of the concentrations of formalde- 
hyde 1-320, 1-240, 1-160, and 1-80, a considerable quantity of 
