LEAD POISONING IN WATEEFOWL. 9 
After experiments had fully established that shot were capable 
of poisoning waterfowl, the question as to whether the diseased con- 
dition was caused by lead or by some other substance present in the 
shot remained to be settled. Arsenic is a common impurity in com- 
mercial lead, and in the manufacture of shot a certain quantity is 
usually added. This is said to be necessary to make the lead pellets 
spherical when dropped and also to harden them. As arsenic and 
lead in combination are used to form poisonous compounds for kill- 
ing insects and for other purposes, it might be supposed that these 
compounds were active in cases of poisoning from shot eaten and 
held in gizzards of waterfowl. In several experiments, therefore, 
ducks were given quantities of granulated lead equal in weight to 
the number of shot that in other cases were found to be fatal. The 
granulated lead had the same effect as the shot in each instance, 
proving that lead was the active agent in the poisoning. Birds 
seemed to die more quickly from the effects of the granulated lead, 
as the particles were numerous and so small that they were readily 
ground up and passed into the intestine to be absorbed. 
PREVALENCE OF SHOT IN MARSH AREAS. 
Many marshes, lakes, and bays in the United States are noted as 
resorts for waterfowl, and are visited each year during the hunting 
season by sportsmen in pursuit of game. Owing to the configuration 
of the land and water areas and the habits of the birds pursued, 
there are points or islands in these places that afford good shooting 
each season, and in many cases blinds to conceal the hunters are lo- 
cated on or near the same spot year after year. In time a great mass 
of waste shot pellets will gather about these points. The action of 
the water, especially where it is more or less saline or alkaline, tends 
to corrode these shot somewhat, but this process is in most cases very 
slow, so slow, indeed, as to be hardly appreciable. As corrosion takes 
place, there forms over the surface of the shot a scale, which, as it 
thickens, protects the lead more and more from further chemical ac- 
tion. There can be no question that shot pellets may last for many 
years. 
To ascertain the presence of quantities of expended shot in these 
marsh areas the writer with an assistant examined the mud near two 
localities in the shooting grounds at the mouth of Bear River, Utah, 
from each of which several thousand shells are fired each season. 
For the first experiment a small island known as Bayless Island 
was selected, on which a blind had been placed each season for about 
20 years. In searching for shot an ordinary sieve with a mesh small 
enough to hold No. 7 shot was used. Mud was shoveled into this 
and washed through the wire. The mud here was soft for a depth 
of 5 inches; below this was a hardened clay. Sifting was begun at 
