Nov. 15, 1924 
Reaction Between Formaldehyde and Proteins 
475 
applies only when the reacting sub¬ 
stances are present in equimolecular 
proportions. In this formula J=time, 
a =amount of substance originally pres¬ 
ent, and x = amount of substance con¬ 
verted. In order to determine the 
values of t , a, and x a definite amount 
of formaldehyde was added to a serum 
of known composition. This was kept 
at a temperature of 25° C. Samples 
were taken at definite periods, the 
euglobulins determined, and from the 
values so obtained the velocity con¬ 
stant ak was calculated. The results 
are shown in the following Table: 
of Experiment II points strongly to the 
probability that the reactions which 
take place in formolized serum belong 
to the second order even though the 
experimental data available may not 
absolutely establish such a conclusion. 
THE EFFECT OF TEMPERATURE 
The effect of temperature on the 
velocity of the reactions which result 
in the production of euglobulins in 
formolized serum was determined by 
the following experiment: 
Table III.— The velocity constant of the reaction taking place in serum containing 
0.74 per cent formaldehyde and kept at a temperature of 27° C 
_ 
15_ 
30.... 
45.. 
60. 
120 .. 
240___ 
360.. 
, Average 
, l X 
*>x 
c a-x 
ak=~j •. —- 
t a—x 
0.00 
6.00 
.92 
5.08 
0.012 
1.46 
4.54 
.010 
1. 87 
4.13 
.010 
2. 55 
3. 45 
.012 
3.30 
2. 70 
.010 
4.28 
1.72 
.010 
5.00 
1.00 
.013 
.011 
°<=time of contact. 
b :r=noneuglobulin protein cover ted to euglobulins. 
*a —original noneuglobulin protein. 
The value for ak in Table III is a 
constant within the range of experi¬ 
mental error. Data from six other 
experiments in which undiluted serums 
were used, and in which t , x, and a had 
been determined were available. From 
these data ak was in each case calcu¬ 
lated and the values so found were in 
each case constant within the range of 
experimental error. However, calcu¬ 
lations of ak from the data obtained 
when diluted serums were used yielded 
decreasing instead of constant values. 
Thus, in the undiluted serum of Experi¬ 
ment II ak was found to have a value of 
0.066 throughout the reaction, but in 
the diluted serum the values calculated 
for ak decreased from 0.033 to 0.015 in 
two hours. This suggests that the 
reaction in the diluted serum was 
approaching equilibrium, and this sug¬ 
gestion would account for the fact that 
a constant ratio was not obtained in 
Experiment II. 
The fact that constant values were 
obtained for ak in the experiment 
reported in Table III and that a ratio 
of 1 : 2 was obtained in the early part 
EXPERIMENT III 
A horse-blood serum of known com¬ 
position was divided into two portions, 
one of which was warmed to a tem¬ 
perature of 39° C. and the other to a 
temperature of 29°. When the serums 
had reached these respective tempera¬ 
tures a formaldehyde solution pre¬ 
viously heated to the respective tem¬ 
perature was added to each in such 
amounts that each serum contained 
1.85 per cent formaldyhyde. The 
serums were maintained at the respec¬ 
tive temperatures for three hours, 
samples of each being taken at inter¬ 
vals for the determination of euglobu¬ 
lins. From the amounts of euglobulins 
found at each determination the 
amount of noneuglobulin protein re¬ 
maining unchanged at each instant 
was calculated by subtracting the 
amount of euglobulins found from the 
total proteins present. The results are 
shown in Figure 2. From this figure 
the time required for given amounts of 
work to be done in the two serums was 
determined by interpolation and is 
shown in Table IV. 
