MISCELLANEOUS LIQUID INSECTICIDES. 55 



aniline dye, Prussian blue, and carbon. The difference between the 

 contents of the filter and the original weight of substance taken is oil. 

 Treat the residue on the filter with 90 per cent alcohol, and wash 

 until aniline d}^e is removed. Dry and weigh. The difference between 

 the weight of the present and former contents of the filter represents 

 aniline dye. None was present in this sample. 



Treat the residue on the filter with about 200 cc of 2 per cent sodium 

 hydroxid and wash with water until free of alkali. Treat the residue 

 with 300 cc of 10 per cent hot hydrochloric acid, continue washing with 

 more dilute hydrochloric acid until the filtrate is free of iron. Wash 

 with hot water, dry, and weigh. The difference between this weight 

 and the former is Prussian blue, and what remains on the filter is 

 carbon. 



Composition of Grub and Canker Worm Exterminator. 



Per cent. 



Oil (appears to be linseed) 87. 28 



Carbon 11. 40 



Prussian blue . . 1. 32 



100 



This substance is a sample of printers' ink, and when smeared around 

 a tree or on a piece of paper tied around a tree, will doubtless prevent 

 the adult females from climbing up the trees and depositing their eggs. 



MISCELLANEOUS LIQUID INSECTICIDES. 

 METHODS OF ANALYSIS AND RESULTS OF DISTILLATION TESTS. 



A few general methods of analysis are applicable to all of these sub- 

 stances. In the first place, a sample is subjected to distillation, and 

 the temperature of the vapor as the distillation progresses and size of 

 the fractions are noted. The odor of the various fractions is noted, 

 much light often being thrown upon the subject thereby. The usual 

 tests for various substances suspected of being present are made in the 

 different fractions. Tests of the miscibility of the samples with differ- 

 ent solvents and of the optical activity often allow us to distinguish 

 certain oils from one another. This is especially true in distinguish- 

 ing kerosene from turpentine and allied products. 



LEE'S LICE KILLER. 



[Serial No. 19627.] 

 Results of distillation test. 



77-100 C. About 3 per cent of light oils clouded with water, and having a pro- 

 nounced odor of benzene, toluene, etc. 



100-180 C. Practically nothing comes over. 



180-220 C. Fifty-two per cent comes over, having the odor of and giving tests for 

 phenol and cresols. 



220-250 C. Thick oil comes over, mixed with naphthalene, and finally at 250 C. 

 the distillation tube become entirely clogged with naphthalene. 



See correspondence with manufacturers, p. 61. 



