October, ’ 18] 
EWING: MOSQUITO BITE PALLIATIVES 
401 
the simple process of submerging the sprinkling sewage filter for twenty- 
four hours with the ordinary sewage as delivered to the sprinkling 
filters without in any way impairing the efficiency of the film upon 
which the activity and efficiency of the sprinkling sewage filter de¬ 
pends. 
THE USE OF PALLIATIVES FOR MOSQUITO BITES 
By H. E. Ewing, Ames, Iowa 
In our literature on mosquito control we find many references to the 
use of different agents for the alleviation of the itching pain that follows 
the bites of the mosquito. Most of these recommendations have been 
based upon “hearsay” reports of acquaintances who had tried them, 
or have been culled from a voluminous correspondence in which dif¬ 
ferent individuals had related their experience with different remedies 
which had proved helpful. Having tried some of these palliatives with 
little effect, the writer determined to make an experimental investiga¬ 
tion of the remedial qualities of the different chemicals that had been 
suggested. 
Theory of Action of Palliatives 
In most cases apparently there has been no theory as to the action 
of the palliatives used or valid reason for applying the same. Each 
individual apparently tried what accidentally suggested itself to his 
mind or what happened to be on hand. At one time it was believed 
that the inflammation and itching sensations caused by mosquitoes 
were due to formic acid or at least to some toxin that was neutralized 
by the application of an alkali. The toxin was supposed to be secreted 
by a specialized lobe of each group of salivary glands. This was the 
theory of Macloskie. The more recent work of Schaudinn and Major 
Williams have shown that the toxin comes not from the salivary glands 
but from one of the esophageal diverticula, and appears to be produced 
by the symbiotic action of a fungus. These more recent demonstra¬ 
tions have demolished the theories based on the belief that the beneficial 
action of an alkaline solution came through its neutralizing effect upon 
the acid poison of the salivary glands. 
Methods 
In testing the various solutions for their effect as palliatives the 
usual experimental methods were employed. Checks were run in each 
case and comparisons made with untreated bites of mosquitoes. Two 
or more mosquitoes, usually of the same species and always from the 
same environment, were allowed, or induced, to feed simultaneously 
