Fig:. 2. Bee cage used in the laboratory. 



The syrup was a 40 per cent solution of cane 

 sugar. To this was added soluble arsenic, sufficient 

 to give .000581 gram to each gram of syrup. "^ 

 A drop of this was placed on a piece of wax founda- 

 tion, and the whole weighed to one-tenth of a milli- 

 gram. This was immediately taken from the balance 

 and slipped under the cage containing the bees. Very 

 soon (almost instantly) a bee would find it and be- 

 gin feeding. The cage was then raised a bit from 

 the board and placed to one side leaving the bee on 

 the foundation in the open. A glass funnel was 

 then placed over the individual (See Fig. 4) and 



In determining the fatal dose of 

 arsenic we proceeded about as fol- 

 lows : Flying bees were taken in front 

 of the hive by first drumming to 

 cause them to fly densely at that 

 place, then while so swarming, a 

 wire cage (See Fig. 2) was dropped 

 over them on to a smooth wide 

 board, thus trapping them. The 

 cages were then moved into the lab- 

 oratory and placed in a dark closet 

 over night; the bees were fed the 

 next morning. When treated in this 

 way they are easily handled, 

 and feed readily when given the 

 syrup. 



1 Examination of dead bees to determine the presence or 

 absence of arsenic was made by the Gutzeit method. Briefly, 

 the laboratory procedure was as follows: 



One bee that had been treated with sodium hydroxide and 

 nitric acid for the removal of arsenic on the surface of the body 

 was placed in a 'test-tube; a little water, an equal amount of 

 hydrochloric acid, and some potassium chlorate were added, and 

 the test-tube placed in a steam bath. Chlorine was evolved, 

 which breaks down the tissue of the body, thus liberating the 

 arsenic. The contents of the test-tube were then evaporated to 

 near dryness to drive off the free chlorine. The residue was 

 then examined in the apparatus shown in Fig.^ 3, w^hich consists 

 of an eight-ounce bottle (d) and three small tubes and stoppers. 

 In the tube just above the bottle (c) a folded filter paper was 

 placed which had been saturated with lead acetate and dried. 

 The tube above this (b) contained a mass of glass wool sat- 

 urated with lead acetate. The last tube (a) contained a small 

 strip of filter paper which had been saturated with mercuric 

 chloride and dried. 



The contents of the test-tube were now placed in the eight- 

 ounce bottle. To this were added hydrochloritj acid, stannous 

 chloride, ammonium ferric alum, water, and zinc' The zinc and 

 acid cause an evolution of gas, hydrogen sulphid, arsine, etc. 

 The sulphides were caught by the lead acetate, and the arsine 

 was passed on to the sensitized mercuric chloride paper, , When 

 arsine is present, the paper turns yellow; if absent, no change 

 is apparent. Figure 5 shows some tests of bees in the control 

 feeding work when the amount of arsenic taken was known. 



Considerable experience by the operator is necessary before 

 reliable results can be obtained. For this work everything was 

 standardized and unusual pains taken to secure accuracy. All 

 materials used "were frequently tested for arsenic, as this method 

 properly handled is delicate enough to show positive results 

 with much so-called chemically pure acid and zinc. 



Fig. 3. Gutzeit meth- 

 od. D (8-oz. bottle) 

 contains emnlsifled bee 

 and reagents; C con- 

 tains filler paper satu- 

 rated with lead acetate 

 then dried; B contains 

 glass wool saturated 

 with lead acetate; A 

 contains sensitized mer- 

 curic chloride paper. 



