128 AGRICULTURAL EXPERIMENT STATION. 



Chloronaptholeum, a product manufactured by the West Dis- 

 infecting- Company, of New York, is used as a general disin- 

 fectant by the New Brunswick Board of Health, of which the 

 writer has been a member for a number of years. A series of 

 experiments proved that this material was effective as against 

 mosquito larvae, even when greatly diluted, and beginning 

 toward the end of May, 1903, all dirty gutters, sewer catch- 

 basins, drainag-e ditches and lot pools in the Sixth Ward, in 

 which I reside, were treated whenever I found a brood develop- 

 ing. The material was diluted with fifty parts of water in the 

 disinfecting- cart and applied with a garden sprinkler until the 

 water in the treated places was milky. As general disinfection 

 was also' aimed at, the material was used to excess in gutters and 

 drainage ditches. The species that breed in these treated places 

 are Culex pipiens, restuans, sylvestris, janiaicensis and Anopheles 

 maculipennis. The result was perfect. Until the arrival of the 

 salt marsh species, about July ist, scarcely a mosquito was noticed 

 on my porch, and after their advent frequent collections showed 

 local forms at rare intervals and in small numbers only. Exami- 

 nations of the treated pools were frequently made, and in every 

 instance it was known that larvae were present and that the appli- 

 cation had killed them. On one occasion the apphcation was 

 delayed until pupae were generally present, and in that case 

 some of the adults emerged. This material shares the weakness 

 of other Cresol preparations, in that it does not kill pupae at a 

 strength which is fatal to the mature larvae. 



For a g-eneral disinfectant, however, this material has a high 

 value as a larvicide, and it is available for general use in places 

 where oils would be objectionable. It does not act well in salt 

 water, however, and is of no use on the marshes where the 

 water is brackish or with more than a mere trace of salt. The 

 cost is about $1 per gallon, or too high where the mosquito alone 

 is aimed at. 



Phinotas oil is a preparation made by the Phinotas Chemical 

 Company, of New York, and it is the most effective larvicide 

 known to me. It acts b}^ poisoning the water and also forming 

 a film over it. When applied from a sprinkling pot or a sprayer 

 in globules, these sink tO' the bottom, begin to dissolve, turn the 

 water milky, and in time seem to take bubble forms, which rise 

 to the surface, burst and spread out in an oily film. This is 

 effective even in the smallest quantities, and larvae and pupae begin 

 to die within a few minutes after the application. Its action is 

 so violent, indeed, that all other aquatic insects and even fish 

 succumb at once. Its very effectiveness limits its use to sewer 

 catch-basins, cesspools and temporary lot pools, for which noth- 



