February, 1913 



THE CANADIAN HORTICULTURIST 



47 



Every Man vvho Sprays His Orchard 

 or Garden — Every Man who Uses 

 Arsenate of Lead — should read this 



rj^ '_ A Comparison of Two Different Kinds of Arsenate of Lead 



GENERALLY speaking, there are two separate 

 and distinct forms of Arsenate of 1-^ad on the 

 market. Neutral and Acid. Neutral Arsenate of 

 Lead is composed of arsenic and lead prepared in such a 

 manner that all the arsenic is thoroughly combined with 

 lead. This material is very light in gravity, settles very 

 slowly in water, is fluffy, amd when sprayed on the foliage 

 clings very tightly to it. 



On account of its fluffinese it luas great covering power and 

 because all the arsenic is thoroughly oomhined with lead it does 

 not change its composition on exposure to the weather, and so 

 will not bum the most delicate foliage. 



In the Acid Arsenat* of Lead, only two-thirds of the arsenic 

 ia neutralized with the lead, the other third being free or loosely 

 combined eo e.s to form a precipitate 'which is insoluble in water 

 at first, but which on exposure to weather begins to disintegrate 

 andi give free arsenic which will severely bum tender foliage. 

 This material is much heavier in gravity, not eo fluffy, settles 

 much more rapidly in a spray mixture when used for spraying 

 purposee and does not cover the area of foUago so thoroughly on 

 account of ite greater density. The reproductions illustrate the 

 difference in the two forms of Arsenate of Lead. One is Sherwin- 

 WilUams New Process Arsenate of Lead, which is the hiteheet 

 type of an absolutely neutral, thoroughly oombtaed material. 

 The other is one of tie typical brands of Acid Arsenate of Lciid 

 offered in oomi)6tition usually at a muoh lower price. This shows 

 very clearly the defects common to an acid form ol Arsenate of 

 Lead. 



Figure 1 shows the two forms of Arsenate of Lead stirred up 

 in water, the same quantity of paste being used in each case and 

 diluted to the same total volume with water. 



Figure 2 shows these same glasses after settling 7 minutes. 

 Figure 3, after settling 15 minutes. 



Figure 4, after they have stood all night and settled all they 

 could. 



After thoroughly settling, the bulk occupied by a given quan- 

 tity of New Process Arsenate of Lead is approximately 45 cubic 

 centimeters, whereas the acid material is 20 cubic centimeters, 

 showing two and one-quarter times greater bulk for New Process 

 Arsenate of Lead. 



From the economy standpoint, S-W New Process Arsenate of 

 Lead will show very satisfactory results. It is not the cheapest 

 brand on the market, but the uniform, high quality maintained 

 more than balances the few cents additional in first cost. 



It is an ideal Arsenate of Lead for fruit-tree or vegetable 

 spraying, because its composition is such that it will not injure 

 the most delicate foliage. Where only a small aanount of spraying 

 is done, such as in the garden or vegetable greenhouse, S-W Pro- 

 cess Arsenate of Ijead is really the only practical material that 

 should be used, due to its adaptability for use on all kinds of 

 foliage with entire safety. It is put up in suitable air-tight 

 packages, which keep it in fresh, usable oondition at all tdmee. 



Fig. I. 



F'g- }■ 



The Sherwin-Williams Co. 



of Canada, Limited 



Fig. 2. 



Fig. 4. 



MANUFACTURERS OF INSECTICIDES 



OFFICES & WARCMOUSESr MONTREAL. TORONTO, WiNNIFEC. VANCOUVER. LONDON. ENO 



