45 
The following observations have been made on the effect of evapora- 
tion and incineration on the power of blood and copper sulfate to 
induce the oxidation of an alkaline solution of phenolphthalin by 
hydrogen peroxide: 
A solution of blood was prepared containing 4.4 milligrams of 
human blood in 100 c. c., and also a M/1000 solution of copper sulfate. 
1. 1 c. c. portions of each of these solutions were evaporated to dryness on a 
steam bath in platinum dishes; the residues were then dissolved in 1 
c. c. of water and 2 c. c. of reagent (4) added. 
2. 1 c. c. portions of each of these solutions were evaporated to dryness on the 
steam bath in platinum dishes and incinerated at a low red heat; the resi- 
dues were then treated with 1 c. c. of water and 2 c. c. of reagent (4) added. 
By way of comparison, tubes were prepared containing — 
V 
3. 1 c. c. of distilled water and 2 c. c. of reagent (4). 
4. 1 c. c. of the blood solution and 2 c. c. of reagent (4). 
5. 1 c. c. of the M/1000 copper sulfate solution and 2 c. c. of reagent (4). 
At the end of five minutes these tubes showed the following 
colors : 
Color. 
Tube. 
Water. 
i 
Blood. 
Copper sulfate. 
Number 1 j 
Deep red (slow) 
Deep purplish red. 
Deep purplish red. 
Number 2 

Faint pink 
Number 3 . . . . 1 
Faint pink 
Number 4 
Deep purplish red 
Number ri 
Deep purplish red. 
e see, therefore, that as the result of evaporation blood loses 
some of its oxidizing power, whereas the activity of copper sulfate, 
as might be expected, remains undiminished. On incineration, 
blood loses, completely or nearly so, its power to induce the oxida- 
tion of an alkaline solution of phenolphthalin by hydrogen peroxide; 
whereas the activity of copper sulfate suffers practically no change 
as the result of incineration. 
The effect of evaporation and incineration on the oxidizing power 
of blood towards alkaline phenolphthalin alone, reagent (2) was 
also tried. 1. 1 c. c. of the blood solution containing 0.044 milligram 
of blood was mixed with 2 c. c. of reagent (2). 2. The residue left 
from the evaporation of 1 c. c. of this same blood solution was dis- 
solved in 1 c. c. of water and 2 c. c. of reagent (2) added. 3. The ash 
left from the incineration of 1 c. c. of the same blood solution was 
dissolved in 1 c. c. of distilled water and 2 c. c. of reagent (2) added. 
After twent}-four hours these tubes showed the following colors: 
1. Deep red. 
2. Light red. 
3. Faint trace of pink. 
