58 INSECTICIDES AND FUNGICIDES. 



fractions, that that fraction of coal tar containing phenol and the 

 cresols, usually termed creosote oil, was principally used. The creo- 

 sote oil has evidently been boiled with resin or fatty matter and 

 sodium hydroxid, which causes it to form an emulsion with water 

 instead of a separate la} 7 er. It is well known that creosote emulsions 

 give good results, both as disinfectants and insecticides. 



DYKE'S LOUSE PAINT. 



[Serial No. 12, I and W.] 



This sample has a coal-tar odor, and has a black substance in suspen- 

 sion, which appears to be carbon. What remains after filtering off the 

 carbon is a green fluorescent oil. 



Results of distillation test. 

 Per cent. 

 80-150 C ....... 3 Light oil; odor of benzene, toluene, etc. 



Has an odor of phenol and cresols, and 



r' ' !s! Thick olls with bad odor; but a11 3 sam - 



:::;:: ill ^^^- 



Remaining in flask 

 and loss ........ 10 



In case this were a sample of pure coal tar the higher boiling frac- 

 tions would be heavier than water. The sample appears to be mainly 

 composed of petroleum along with some coal tar, or one of its frac- 

 tions as creosote oil. Carbon is present in suspension. The results of 

 using this as a louse exterminator would very likely be good. The 

 preparation should not be applied in too concentrated a form, as it 

 would burn the skin badly. 



CHLORO NAPTHOLEUM. 

 [Serial No. 13, I. and W.] 

 Results of distillation test. 

 Sample has a strong odor of coal tar. 



80-105 C. A fair-sized fraction, separating into a layer of water and a layer of 

 light oils having the odor of benzene, toluene, etc. , comes over. 

 105-180 C. Only a few drops of liquid come over. 



180-220 C. A small amount of a tljick oil comes over having the odor and giving 

 tests for phenol and the cresols. At about 200 the mass in the retort becomes 

 semisolid. 



220-225 C. A few drops of oil come over, and at the latter temperature the con- 

 denser becomes so stopped up with naphthalene that the distillation must be stopped. 

 Sodium oxid, 1.99 per cent, and traces only of sodium chlorid. 



This sample appears to consist of creosote oil, perhaps enriched with 

 naphthalene, which has been boiled with resin, fatty matter, and sodium 

 hydroxid to cause it to form an emulsion with water. 



a See correspondence with manufacturers, page 62. 



