23 



Treat the potatoes as with the formalin. As no better results were 

 obtained by me with the corrosive sublimate than with formalin, and as the 

 first is an intense and lasting poison whilst the latter is not, I advise the use 

 of formalin. 



No. 16. — Potassium Sulpliidc: — 



This is a hard substance of a brown colour when fresh, though turning on 

 the outside yellow on exposure to air or sunlight. It is. from its colour, often 

 called " Liver of Sulphur." It sh(juld be kept in a closed vessel not exposed to 

 sunlight. 



Totassium sulphide Vj oz. to 1 oz. 



Water 1 gallon. 



This spray is used for most of the powdery mildews, but I have had best 

 results with it in combatting mildew ou the gooseberry. Four or five sprayings 

 will do away with mildew, when on previous years it has been so bad as 

 entirely to spoil the crop. It dissolves readily in water slightly warmed, while 

 it never clogs the nozzle, so perfect is Its solubilit.v. I found three sprayings 

 would completely save the crop, but that one or two more were needed to do 

 away with the disease completely. The first spraying should be applied just 

 as the yo\ing leaves are putting forth, and the subsequent applications two or 

 three weeks apart through the growing season, 



Arscnite of Lime irilli .S'orfa : — 



White arsenic 1 rb- 



Sal soda (crystal) 4 ms. 



Water 1 gal. 



The ingredients are boiled in the required amount of water until dissolved, 

 which will take place in a comparatively few minutes, after which the water 

 lost by evaporation is replaced. To every 40 or .">0 gallons of water a pint of 

 this stock solution and from 2 to 4 pounds of fresh slaked lime are added. The 

 chemical compound derived from tlie combination of the sal soda and the white 

 arsenic is arsenite of soda. In the presence of lime this breaks down and 

 arsenite of lime is formed. It requires 4.4 lbs. of crystal sal soda, or 1.6 lbs. 

 of dry sal soda to combine with 1 lb. of arsenic and 2 lbs. of freshly slaked 

 lime to combine with 1 lb. of arsenic to form arsenite of lime. It is always 

 desirable to have an excess of lime present, in order to prevent all danger of 

 burning; furthermore, this excess is a convenience to fruit growers, because 

 they can see by the distribution and amount of lime in the foliage how well 

 the spraying has been done. The formula, which is the Kedzie formula, with 

 a few minor changes, has been used in many different sections of the country 

 with unvarying success. In all of the practical tests under the advice of the 

 writer, this solution is used and is found to be not only as efficient as other 

 solutions, but far cheaper. 



When it is desired to u.se Bordeaux mixture with this solution, it is added 

 to the Bordeaux mixture in the same proportion as to a similar quantity of 

 water.— C. B. Simpson, Bull. .',1, V. S. Div. Ent. 



The above combination of arsenite of lime with soda is preferable to arsen- 

 ite of lime on account of the difficulty in making this latter combination per- 

 fectly, and. when this is not the case ,the free arsenic is very destructive to 

 foliage. 



