36 
rose red color depending on the amount of blood present. Arnold 
(6) has adapted Hellers method to the examination of blood spots 
by dissolving the spot in an aqueous solution of caustic potash, 
adding urine, and heating the mixture. Similarly Parisot (cited by 
Le Canu, 99) adopted the plan of heating the urine, when if blood 
is present it is found in the coagulum. 
BLOOD IX UKIXE. 
Obviously Heller's test iu its original form is more or less crude 
unless further controlled by some such test as the phenolphthalin 
reaction, for the reason that as compared with the quantities of 
blood which can be recognized by phenolphthalin the cpiantities of 
blood required to impart a visible coloration to such a precipitate 
are relatively large. 
In connection with the phenolphthalin test we have employed 
the adsorption and concentration of the blood pigments from urines 
containing blood with good results, as may be seen from the fol- 
lowing: 0.0026 gram of blood was dissolved in 100 c. c. of the urine 
of the same iudividual from whom the blood was obtained and 
labeled (1). Some of the original urine was reserved for comparison 
and labeled (2). One c. c. of urines (1) and (2) were mixed with 
2 c. c. of redistilled water and two drops of thick alumina cream, 
and by way of further comparison a third tube was prepared con- 
taining 3 c. c. of redisthled water and two drops of alumina cream; 
this was labeled (3). The tubes containing these mixtures were 
then shaken and filtered through smaU filters and the residues 
washed with smah amounts of dLstfiled water. Very small amounts 
of the residues thus obtained were added to 2 c. c. of the phenol- 
phthalin-hydrogen peroxide reagent and aUowed to stand five minutes 
at ordinary temperature, at the end of which time the solutions 
showed the foUowing colors: 
(1 Reddish purple. 
(2 1 Faint pink. 
(3 1 Faint pink. 
It is evident, therefore, that by tins procedure we were able to 
recognize 0.000026 gram of blood at a total chlution of 3 c. c., or 
approximately 8 parts of blood per 1,000,000. As a matter of fact 
we reaUy recognized a considerably smaUer quantity than this for 
the reason that only a smaU amount of the aluminium hydroxide 
residue containing the blood was employed in making the test. Or 
looked at in another way, we have been able to recognize definitely 
the oxidizing effect of 26 parts of blood in 1,000,000 parts of urine. 
Tins, I think, is a much smaller amount than could be recognized 
with certainty by spectroscopic or microscopic tests, or indeed by 
