6 BULLETIN 875, U. S. DEPARTMENT OF AGRICULTURE. 
three and can be avoided very easily by careful washing of the hands 
and face before eating or drinking. 
Inhalation is a danger which is constantly present and is difficult 
to avoid except by the use of dust masks or some type of filtering 
arrangement which removes the dust from the air entering the mouth 
and nostrils. 
Absorption undoubtedly is a very important means of taking 
arsenic into the human body. Even if extreme precautions are taken 
during dusting operations to avoid excessive direct contact with the 
poison supply, there is still a very considerable amount of poison 
dust settling all over the body from the air. This also has a decided 
tendency to adhere to the skin and “shed” water unless a strong | 
lather is utilized, so a hasty rinsing in clear water should not be con- 
sidered as a satisfactory means of removing the poison. 
The danger of poisoning, although slight, should be considered. 
In the work conducted under the direction of the writers large 
quantities of calcium arsenate have been used by all sorts of laborers 
and generally with extreme carelessness. In spite of this, however, 
very few definite symptoms of even the slightest arsenical poisoning 
have been observed in connection with the field operations, and these 
tew undoubtedly would have been avoided if proper precautions had 
been taken. Anyone using dry powdered calcium arsenate need not 
tear poisoning if he is reasonably cautious, but if any unexplained ill- 
ness should develop during its use the possibility of poisoning should 
be borne in mind and a physician consulted. The preliminary symp- 
toms of arsenical poisoning differ widely, but generally involve an 
intestinal and digestive disorder and are usually accompanied by 
some form of skin eruption. 
An additional indirect danger to live stock should be considered. - 
The cloud of poison frequently has a tendency to drift considerable 
distances. Conditions may be such that a dangerous amount of 
poison will drift into a neighboring pasture and injure some of the 
stock feeding on the grass. Stock should certainly not be allowed 
to graze on headlands and turnrows in fields which are being poi- 
soned. The same applies to chickens, turkeys, and other fowls. The 
only fatalities the writers have observed in the course of poisoning 
work have been in the case of chickens and turkeys running in 
poisoned fields and picking in the débris covered with a heavy dos- 
age of poison, where the machine had stopped and covered the ground 
rather thoroughly. 
PLANT INJURY BY CALCIUM ARSENATE. 
lt is well to explain briefly the usual nature of arsenical injury 
to cotton plants, as there is a tendency on the part of inexperienced 
