THE STATE ENTOMOLOGIST. 99 



ress eastward, came thick from Wisconsin and Indiana; b n't no or- 

 ganized effort was made to check it, and indeed there was very little 

 chance of doing so. It is fast spreading through Ohio ; and accord- 

 ing to <Dr, Trimble of New Jersey, has already reached Pennsylvania. 

 Uncle Sam cannot Well prevent its spread around the southern shore 

 of Lake Erie, through Pennsylvania and eastward; but, if it can be 

 effectually resisted between Point Edward and the Detroit river, 

 there will be little difficulty in preventing its crossing at Niagara. 

 A victory would indeed be gained if, by intelligent effort, this griev- 

 ous pest could be kept out of Upper Canada, while it is devastating 

 the potato fields on all sides in the States ; and Minister Carding 

 would add to his well-deserved popularity by making the effort, 

 whether it succeeds or not. 



PARIS GREEN A REMEDY. 



While on this subject it may be well to say a few words about the 

 use of Paris green. This substance "lias now become THE remedy 

 for the Colorado Potato Beetle, and it is the best yet discovered. 

 Having thoroughly tested it ourselves, and having seen it exten- 

 sively used, we can freely say that, when applied judiciously, it is effi- 

 cient and harmless. If used pure and too abundantly, it will kill the 

 vines as effectually as would the bugs, for it is nothing but arseniteof 

 copper (often called '^Scheele's green" by druggists), and contains a 

 varied proportion of arsenious acid, according to its quality — often as 

 much as fifty-nine per cent., according to Brande & Taylor. But when 

 used with six to twelve parts, either of flour, ashes, plaster or slacked 

 lime, it causes no serious injury to the foliage, and just as effectually 

 kills the bugs. The varied success attending its use, as reported 

 through our many agricultural papers, must be attributed to the dif- 

 ference in the quality of the drug. 



We hear many fears expressed that this poison may be washed 

 into the soil, absorbed by the rootlets, and thus poison the tubers; 

 but persons who entertain such fears forget that they themselves 

 often apply to the ground, as nourishment for the vines, either ani- 

 mal, vegetable or mineral substances that are nauseous, or even poi- 

 sonous to us. Animal and vegetable substances, of whatsoever na- 

 ture, must be essentially changed in character and rendered harmless 

 before they can be converted into healthy tubers, and a mineral poi- 

 son could only do harm by being taken with the potatoes to the ta- 

 ble. That any substance, sprinkled either on the vines or on the 

 ground, would ever accompany to the table a vegetable which de- 

 velops underground, and which is always well cooked before use, is 



* The Rev. C. J. S. Eethune, in the Canada Farmer for October 15th, 1370, also recommended 

 the marking off of a tract of country about ton mile? in width, all along the border line betwi en 

 the loot of Lake. Huron and the head of Lake Erie, with the exception, possibly, of a portion of 

 •the eastern shore of Lake St. Olair, and stopping the culture of the potato throughout that whole 

 tract during the prevalence of the pest in the neighboring State of Michigan. 



