FORTIETH ANNUAL REPORT. 75 



Several firms have put in applications to be allowed a sort of sliding 

 guarantee, in one case fixing it at 15 to 25 per cent. This of course 

 would actually guarantee only 15 per cent, and if the use of such a 

 guarantee and label were allowed, the fact that 25 per cent appeared on 

 the label, might make it pos.sible for unscrupulous dealers to give un- 

 suspecting purchasers the impression that they could really expect to 

 obtain 25 per cent of sulphur in solution, while the guarantee on the 

 label, "15 to 25 per cent," would only assure them the minimum amount 

 mentioned. Not only does it insure to the purchaser that he is getting 

 the worth of his money if a definite guarantee is given, but the results 

 are far more likely to be satisfactory. 



The manufacture of lime-sulphur solution has reached such a stage 

 that there should not be a variation of more than one per cent in the 

 amount of sulphur in solution in the difl'erent lots as they are barreled, 

 and by endeavoring to keep the per cent of sulphur one per cent above 

 the guarantee, it should be a safe thing for the manufacturer. 



The analyses made during the year indicate that fully 90 per cent 

 of the sulphur in solution is in the form of a sulphide, which is be- 

 lieved to be the most effectual portion of the solution. It can then be 

 stated that the value of a given brand will be almost in exact propor- 

 tion to the per cent of sulphur it contains, so that a brand containing 

 20.00 ]ier cent of sulphur is really worth one-third more than a brand 

 which has but 20.00 per cent of sulphur. 



>VhiIe it was not possible to do very much in the way of making an- 

 alyses of the many brands of insecticides on the market, as is desir- 

 able if the full benefit of the law is to be secured, the use of lime-sul- 

 phur solution has become so general and extensive that arrangements 

 were made to make at least one analysis of each brand sold in Michigan, 

 and in every case they were found to be above the guarantee. 



There are more than a dozen brands of arsenate of lead which have 

 received permits in Michigan, and practically all of them show more 

 than 15 i>er cent of arsenate oxide, with only about one-lialf per cent 

 in a soluble form. As this insectitude does not burn the most tender 

 foliage even when used at the rate of two pounds in fifty gallons of 

 water, which provides about twice as much arsenic oxide as can be used 

 Avith safety in the form of Paris green, the increased efficiency of this 

 material as an insecticide can be readily seen. Then, too, its superior 

 adhesive properties, render its effects much more lasting, and for this 

 reason alone it should be used rather than Paris green. 



There are also some ten brands of Pordeaux mixture which have 

 received permits, but their use is not likely to be very extensive, as 

 lime-sulphur solution seems likely to take the place of Bordeaux mix- 

 ture as a summer spray for most classes of fruit. While each package 

 bears a label Avhich shows the amount of copper sulphate contained in 

 the mixture, it does not guarantee that it will gi^^e the full strength 

 Bordeaux Avhen diluted as directed. One of the brands submitted, but 

 which has not received a permit, would provide less than one pound of 

 copper suphate in 50 gallons if used as directed. 



The tendency of fruit growers to purchase ready prepared spray mix- 

 tures has led to the placing on the market of a number of bi-ands 

 which on their very face are fiauds, or Avhicli are sold at a price ten to 

 fifty times the cost of the materials. One firm has asked for a permit 



