August, ’24] 
TIETZ: ARSENATE SOLUBILITY IN BEES 
475 
present in the reagents. Titrating aliquots of this blank, the results were 
as follows.— 
Blank aliquot..No. 1—.04 c. c. 
“ No. 2—.04 c. c. 
The final determinations were:— 
Oesophagus 
.11 c. c. minus 
.04 c. c. (blank) = .07 c. c. final reading 
H. Stomach? 
.13 44 
“ 44 44 =.09 c.c. 44 
-j-Stomach ) 
Intestine 
.30 “ 
44 44 44 =.26 c.c. 44 
Cheek 
.11 “ 
44 44 44 =.07 c.c. 44 
The next step was to take a standard solution of soluble arsenic and 
titrate with the same iodine. When this was done, it was found that it 
took 41.01 c. c. of iodine to neutralize 25 c. c. of this standard solution. 
Twenty-five c. c. of the standard solution was known to contain .025 
grams of As 2 0 3 , so one cubic centimeter of iodine would neutralize 
.025 
^ or .000609607 g. of As 2 0 3 . To find the grams of As 2 multiply the 
As 2 0 3 factor by .75748 and for As 2 0 5 multiply the same factor by 1.- 
16168. These factors are based on atomic weights. The final factor for 
As 2 determination was .00046176511036 grams As 2 for every c.c. of 
iodine used (.000609607 X .75748) and the grams of As 2 0 5 neutralized 
by every c.c. of iodine was equal to .00070816825976 (.000609607 X 
1.16168). 
Having made these determinations they were then used in comput¬ 
ing the As 2 and As 2 0 5 present in the samples and check. These compu¬ 
tations were as follows:— 
Oesophagus 
.07 c. c. iodine X .000461765 = .0000323255 grams As 2 in an aliquot 
.07 c. c. iodineX.0007081682 = .000049571774 grams As 2 O s in an aliquot 
Honey Stomach plus Stomach 
.09 c. c. iodine X .000461765 = .00004155885 grams As 2 in an aliquot 
.09 c. c. iodine X .0007081682 = .0000637335138 grams As 2 0 5 in an aliquot 
Intestine 
.26 c. c. iodineX.000461765 = .0001200589 grams As 2 in an aliquot 
.26 c. c. iodine X .0007081682 = .000184123732 grams As 2 0 5 in an aliquot 
Check 
.07 c. c. iodineX.000461765 = .0000323255 grams As 2 in an aliquot 
.07 c. c. iodineX.0007081682 = .000049571774 grams As 2 0 s in an aliquot 
Since each aliquot was 1/10 of the total amount (100 c. c. of 1,000 
c. c.) these results must be multiplied by ten to get the number of grams 
of As 2 and As 2 0 5 rendered soluble by the digestive fluids and the water 
check. If we wish to reduce the quantities to per cents it is necessary to 
