Page 10 



is necessary to consider the relative 

 cost of each. 



The percentage of water soluble ar- 

 senic which a sample contains has 

 been believed for many years to in- 

 dicate the degree of injuriousness to 

 the foliage of plants. Obviously only 

 that arsenic which is brought into so- 

 lution in the water used in spraying 

 can be absorbed into the leaf sub- 

 stance and only that which is ab- 

 sorbed can injure the leaf. There- 

 fore, in judging the quality of an ar- 

 senical insecticide it is always neces- 

 sary to know the percentage of water 

 soluble arsenic. Potato vines are not 

 easily injured by arsenic and a much 

 higher percentage of soluble arsenic 

 is permissible in spraying them than 

 in spraying delicate foliage like that 

 of the peach. It follows then that a 

 low water solubility such as is found 

 in arsenate of lead is of no particular 

 advantage in a poison for the potato 



Blight -Proof 



Surprise Pear Stock 



ON 



Japan Root 



Don't worry about blight taking your 

 pear orchard. Plant the blight-proof 

 Surprise and insure against loss. 

 The following year topwork it to 

 Bartlett, Bosc or any desired variety 

 and you have a blight-proof trunk 

 and framework. This method is 

 endorsed by Prof. Reimer of the 

 Southern Oregon Experiment Sta- 

 tion, Talent, Oregon, and recom- 

 mended by him after extensive ex- 

 periments. Thousands of these trees 

 have been planted the last few years 

 in California and Southern Oregon, 

 and to some extent in the Yakima 

 Valley, Washington. Our buds were 

 secured direct from Prof. Reimer. 



For other dependable 



Fruit Trees, 

 Shade Trees, 

 Roses, Vines, 



Etc., write 



Washington Nursery 

 Company 



Toppenish, Washington 



Agents Everywhere 



More Wanted 



BETTER FRUIT 



beetle, while it is an advantage in the 

 spraying of fruit trees. 



The next column in the table deals 

 with the sticking quality, but we shall 

 consider the column on texture at the 

 same time. By texture it is intended 

 to mean the degree of fineness of the 

 powder. If examined under a low 

 power microscope, a wide difference 

 of fineness will be found in the vari- 

 ous kinds of arsenicals. Paris green 

 is coarse and the granules examined 

 with a microscope appear like so 

 many rocks on a plane surface. They 

 are easily brushed off by showers of 

 rain and the sticking quality naturally 

 is poor. The same principle holds 

 throughout and the more finely di- 

 vided powder has a better sticking 

 quality. A good sample of arsenate of 

 lead is exceedingly fine. The precip- 

 itate is practically amorphous and 

 when the water once dries out, leav- 

 ing the poison on the foliage, it is not 



Nice Bright Western Pine 



FRUIT BOXES 



AND CRATES 



Western Pine Box Sales Co. 



SPOKANE. WASH. 



November, 1920 



easy to loosen it again. Foliage which 

 has been sprayed in the spring may 

 be found still white with the poison 

 in the fall. 



The settling quality is governed 

 mainly by the texture of coarseness 

 and by the specific gravity. It will be 

 seen in the table that the settling qual- 

 ity very closely parallels the coarse- 

 ness of the powder. 



The cost per pound, as given in the 

 table, is based on prices this spring 

 and these prices are wholesale at the 

 factory in 100 pound lots. It is no- 

 ticeable that the prices of Paris green 

 and arsenate of lead are high com- 

 pared to the percentage of arsenic 

 which they contain. This is especi- 

 ally true of arsenate of lead. With 

 these facts before you it is possible 

 to choose for yourself between these 

 insecticides, but certain statements 

 should be made regarding some of 



Continued on page 16. 



ADVERTISERS MENTION BETTER FRUIT 



