64 
JOURNAL OF ECONOMIC ENTOMOLOGY 
[Vol. 16 
liquor” and is utilized in the manufacture of ammonium sulphate. It 
contains 14-15% of ammonia. Otherwise its exact composition is 
unknown. 
These were tested in small experiments in which the plots were ar¬ 
ranged in triplicate as follows: 
Plot 1. Cresylic Acid. This material contained approximately 80% total 
cresols, as well as a small proportion of phenol and some of the higher boiling tar 
acids. 
Plot 2. Crude Naphthalene. This was a crude material containing around 
85-90% of actual naphthalene, the remainder being oils that mainly accompany 
naphthalene. 
Plot 3. Pyridine bases, the crude commercial product. 
Plot 4. Crude Cresylic Acid, 95% dark—a crude dark colored acid containing, 
however, 95% of tar acids. The tar acids may be anything from phenol up to the 
higher homologues. 
Plot 5. Neutral Hydrocarbon Oil. 
Plot 6. “Residue.” Under this name was used a residue rich in pitch and the 
higher hydrocarbons such as phenanthrene, to the practical exclusion of the other 
classes of compounds. 
Plot 7. Crude Xylenols. These came from tar acids boiling mainly above the 
cresols and regarding the exact composition of which very little is known. 
Plot 8. Crude Anthracene. This was 20-25% material, containing all the 
other materials such as carbazol, phenanthrene and other solid hydrocarbons of the 
aromatic series. 
Plot 9. Anthracene Oil. 
Plot 10. Check. No treatment. 
Plot 11. “Gas tar.” 
It is not thought necessary to record the actual figures from these 
experiments, since, as only 105 plants were used in each, the actual 
standing of the different treatments would have little significance. It 
is sufficient to record that with 15% of the check plants destroyed, 
casualties of a single plant were recorded from 2 treatments only, viz., 
naphthalene and crude xylenols. It is evident that all the main classes 
of products entering into the composition of creosote have a marked 
insecticidal or repellent value. 
Effect of Treatments upon Eggs and Larvae 
In ascertaining what latitude we may have in applying the different 
treatments, we must find out whether the material acts merely to repel 
the flies or whether it acts directly upon the eggs or upon the larvae 
and to what extent they are most effective against maggots of different 
ages. Accordingly, experiments with this point in view were carried 
out with corrosive sublimate and creosote dust. 
