220 R. W. GLASER. 



the alkali was entirely too strong and prevented the appearance 

 of a red color. Hence, it proved to be necessary to resort to a 

 finer reagent. The phenolphtha/m had first to be isolated as 

 such. A quantity of reagent for occult blood was taken, hydro- 

 chloric acid was added till the precipitate that formed had 

 redissolved. The solution was extracted with ether which was 

 washed 3-4 times with small quantities of water to get rid of 

 the acid. The ether was then evaporated without heat in hydro- 

 gen. The evaporation in an indifferent gas is safer, although 

 not absolutely necessary, for I find that the phenolphtha/'m 

 crystals will keep splendidly if stored in very small vials especially 

 when they are filled to the brim before corking so as to exclude 

 the air. Both methods were tried, however. On evaporation 

 one obtains a crust of phenolphtha/w which may, if desired, 

 be crystallized from alcohol or a mixture of ether and petroleum 

 ether, which should evaporate spontaneously. 



A small piece of phenolphtha/w was now placed in a drop of 

 pancreatic extract to which a drop of a }/^ per cent. KOH solu- 

 tion and a drop or two of a 3 per cent, solution of hydrogen 

 peroxide had been added. All work was done under oil. The 

 characteristic red color was immediately obtained. Control tests 

 with water were performed each time. 



The great quantity of KOH ordinarily used in making the 

 reagent for occult blood is necessary to reduce the phenolphthalem 

 to phenolphtha/fw. But after this is accomplished the excess of 

 KOH must be gotten rid of as described above, otherwise the 

 color will not develop when such infinitesimal quantities of 

 extract have to be dealt with. A drop or two of }/2 per cent. 

 KOH solution seems to be just the proper amount and concentra- 

 tion to obtain the red salt. 



In the last experiment with the hog extract two drops of 

 extract were used; a crystal of phenolphtha/w was added and to 

 this one drop of 3/2 P er cent. KOH solution plus one drop of 

 hydrogen peroxide. The characteristic red color was imme- 

 diately obtained. I repeat, as this is very important, that all 

 work was done under oil. Control tests likewise accompanied 

 the actual tests. 



Two drops of cenocyte extract were now taken, treated in 



