126 American Fisheries Society 



The crude oils and asphalts caused no toxic effect at all. In 

 the case of the former no toxic substance is thought to be present, 

 in the latter case the substance is in the form of a solid, insoluble 

 mass. Gas house products were somewhat soluble and exceedingly 

 toxic. 



In many cases of road construction the gravel is spread, rolled, 

 and the tar is then sprinkled over the surface by means of a 

 sprinkling tank similar to those used for watering the streets. In 

 many cases but little attention is paid to the condition of the 

 ground or to the weather. The writer has seen roads being oiled 

 during periods when rains were frequent and the roads were 

 moist. Under these conditions of spreading, the tar has been 

 noticed along the sides of the roads where it had been washed by 

 the first rain after laying. 



It has been observed that when roads are tarred during the 

 course of construction, the tar being distributed throughout the 

 whole bed and not only over the surface, and a thin layer of sand 

 spread after the final treatment with tar, no appreciable amount 

 washes away unless there is considerable rainfall during the first 

 day or two after treatment. 



A sample of concentrated waste sulphite liquor was obtained 

 from the Office of Public Roads. It is obtained by concentrating 

 the crude liquor obtained in the manufacture of paper pulp by the 

 ■sulphite process. It is used quite extensively in the treatment of 

 macadam and gravel roads. This sulphite liquor is freely soluble 

 in water to which it gives a color varying from a light straw to a 

 dark brown, depending upon the concentration. 



Fish placed in solutions of 333 parts : 1,000,000 parts of water 

 were not killed in two weeks yet at times they would show some 

 signs of distress. Fish died within two weeks in solutions of 1333 

 parts : 1,000,000 of water. Though they did not show typical 

 signs of poisoning, as the fish killed by other materials did, they 

 were doubtless killed by this concentration of the waste. Some 

 irregularity of the effect of the liquor upon fish in different exper- 

 iments was noted. Marsh* has noted this and attributed it to 

 individual variation. 



* Marsh, M. C; Effect of some Industrial Wastes on Fishes: The 

 Potomac River Basin, Water-supply and Irrigation Paper No. 129, Govern- 

 ment Printing Office, 1905. 



