6 N". C. Agricultural Experiment Station 
corporated a material that would stain the digestive content and indicate just when 
the food passed out of the body. The materials, or indicators were lampblack, methy¬ 
lene blue, and gentian violet. 
DATA 
Test No. 1: White Plymouth Rock hen, leg band No. B36, weight 5.9 pounds. 
8 a. m. given 20 gms. wheat middlings mixed with water and lampblack. 
2 p. m. first evacuation, a trace of lampblack appeared. 
4 p. m. still only a trace of lampblack appears, fed 20 gms. wheat middlings 
without lampblack. 
6 p. m. evacuation showing excreta decidedly black. 
8 a. m. second day 20 gms. middlings and water given. 
8 a. m. third day—48 hours—excreta showed slight tinge of lampblack on the 
outer surface but none on the inner particles. 20. gms. middlings mued 
with water given. 6 p. m. 20 gms. middlings mixed with water given. 
8 a. m. fourth day—72 hours—excreta normal. No trace of lampblack. 
Lampblack appeared in six hours and disappeared in seventy-two hours. 
Test No. 2: White Plymouth Rock hen, leg band No. 142, weight 6.8 pounds. 
8 a. m. given 20 gms. wheat midd ings mixed with water, lampblack. 
4. p. m. fed 20 gms. wheat middlings with water and lampblack. 
6. p. m. first excreta passed. Lampblack stained excreta. 
8 a. m. second day, 20 gms. middlings given. 
6 p. m. 20 gms. middlings given. Excreta still black. 
8 a. m. third day 20 gms. middlings given. Excreta nearly normal, only small 
amount on the outside, inside of mass not containing lampblack. 
6 p. m. 20 grams middlings given. 
8 a. m fourth day—72 hours—excreta normal. 
In this case the first excreta voided after the feeding of the lampblack was at 6 p.im, 
or ten hours. At this time lampblack in small amounts appeared. All lampblack had 
disappeared at the end of 72 hours. 
Test No. 3: White Plymouth Rock hen, leg band No. B10, weight, 6.14 pounds. 
7 a. m. fed 10 gms. wheat middlings mixed with water and lampblack. 
1 p. m. first evacuation. The excreta was black. 
2 p. m. second evacuation. Excreta black. 
7 a. m. fourth day. Excreta free from black. 
Lampblack appeared in six hours and disappeared in seventy-two hours. This test 
was run with a broody hen. , 
Test No. 4: White Plymouth Rock hen, leg band No. 473, weight 5.14 pounds. 
7 a. m. fed 10 gms. wheat middlings mixed with water and lampblack. 
4 p. m. fed 20 gms. middlings, no lampblack. No excreta was voided on the first 
day after feeding with lampblack. Excreta showed black at 7 a. m. second 
day. Excreta were also voided at 7:30 second day which was also black. 
This bird acted as though constipated and no further excreta were voided 
until morning of the fourth day or seventy-two hours. No lampblack 
was present in these last excreta. 
Owing to the fact that no excreta were voided on the day of feeding of 
the middlings and lampblack it is impossible to tell how long it required for 
the lampblack to pass the entire length of the digestive tract. The fact 
that the excreta were free from lampblack on the fourth day and after the 
seventy-two hours showed this test to be in line with those above. This 
test was run with a broody hen. 
