48 
The results obtained with reagent (4), alkaline phenolphthalin 
containing hydrogen peroxide, are given in Table III: 
Table III. 
No. of 
Tube. 
Substance. 
Color, after fifteen minutes. 
Water 
Blood 
Chromic alum 
Potassium chromate 
Potassium dichromate 
Ferrous sulfate 
Ferrous ammonium sulfate. 
Ferric alum 
Potassium ferrocyanide 
Potassium ferricyanide 
Sodium nitroprusside 
Nickel nitrate 
Cobalt chloride 
Cupric chloride 
Cupric sulfate 
Cupric sulfate, M/1000 
Manganous sulfate 
Manganous chloride 
Silver nitrate 
Mercuric chloride 
Lead chloride 
Lead acetate 
Potassium chlorplatinate... 
Sodium chloride 
Potassium nitrate 
Faint trace of pink. 
Deep purplish red. 
Deep pink. 
Faint trace of pink. 
Faint pink. 
Faint trace of pink. 
F aint trace of pink. 
F aint trace of pink. 
Faint trace of pink. 
Decided pink. 
Trace of pink. 
Faint trace of pink. 
Faint yellowish. 
Deep purplish red. 
Deep red. 
Deep purplish red. 
Yellowish. 
Yellowish. 
Brownish, turbid. 
Decided pink. 
Decided pink. 
Trace of pink. 
Trace of pink. 
Trace of pink. 
Faint trace of -pink. 
The only substances, therefore, showing decided oxygen-carrying 
power towards reagent (4) are blood, copper salts, and chromic alum, 
in order of activity. Mercuric chloride, Xo. 20, lead chloride, Xo. 21, 
and potassium ferricyanide, Xo. 10, also show some oxygen-carr}ung 
power; this is slight, however, as compared with blood. 
A comparison of the conduct of such of these substances as show 
certain resemblances to blood, towards the two phenolphthalin 
reagents, reveals certain interesting differences between such sub- 
stances and blood. Thus we see that while silver nitrate oxidizes 
phenolphthalin in alkaline solution it fails to oxidize it when hydrogen 
peroxide is present. As already pointed out, copper salts rapidly 
oxidize an alkaline solution of phenolphthalin containing hydrogen 
peroxide, but fail to oxidize it in the absence of hydrogen peroxide, 
or oxidize it very slowly, much more slowly than blood. Chromic 
alum also oxidizes an alkaline solution of phenolphthalin containing 
hydrogen peroxide, but failed to oxidize it in the absence of the 
peroxide. Potassium clilorplatinate oxidizes an alkaline solution 
