August, ’24] 
TIETZ: ARSENATE SOLUBILITY IN BEES 
473 
mediately dissected and their alimentary, tracts divided into three 
portions (oesophagi, h'oney stomachs plus stomachs, and intestines) 
and each of the portions was placed in 20 c.c. of neutral water. To 
each flask of water plus its portion of the digestive tracts, was added 
exactly one gram of arsenate of lead powder, and to 20 c.c. of neutral 
water alone was also added one gram of the same powder. This last 
flask was, of course, used as a check. At this point in the experiment, 
the writer had the choice of two procedures. In the first place, the 
portions of the alimentary tracts could have been washed for several 
hours in the neutral water, then filtered off and the arsenate of lead 
added to the filtrate. The second way was to add the arsenate of lead 
immediately to the water plus its portions of the alimentary tracts. 
Both ways have their merits and faults. In adding the arsenate to the 
filtrates there is the possibility of obtaining not only a solution of the 
digestive fluids but also, because the portions of the alimentary tracts 
would have to stand several hours in the neutral water before filtering, 
the chance of getting into the filtrate the products of cellular decompo¬ 
sition that would effect the results by increasing the solubility of the 
poison. The second method in which the arsenate is added immediately 
would prevent the formation of decomposition products for arsenic in 
the body acts as a preservative. This point has been noted by many 
writers who have performed autopsies on arsenically poisoned animals. 
One bad feature of this latter procedure is that the cells undoubtedly 
absorb some of the soluble arsenic. The arsenic then, very likely, be¬ 
comes bound up with the protoplasm itself and so does not pass into the 
filtrate. In other words the filtrate obtained does not contain the total 
amount of arsenic rendered soluble by the digestive fluids. 
While it was true that the Ph -f- did not change when the portions 
stood 24 hrs., the writer chose the latter method in order to feel sure 
that the arsenate of lead was not being acted upon by the products of 
putrefaction. 
The contents of the flasks were agitated several times, then at the end 
of 24 hrs. were filtered. The check was treated in the same manner. 
In filtering, a triple filter was made using Schlucher and Schiile No. 
589, 11 cm. paper. The filtrates were re-filtered eight times in order 
that they should contain nothing but the soluble arsenic i. e., to pre¬ 
vent any undissolved arsenate of lead powder from passing into the 
final filtrates. 
To the four final filtrates, namely, from the three portions of the 
alimentary tract and the check, was added 5 c.c. of concentrated nitric 
