REPORT OF COMMITTEE ON PUBLICATION 165 



Flour: Before the development of the modern grinding and bolting 

 machinery, the process of sublimation was depended upon entirely for the 

 production of sulphur in a very finely divided condition. For this reason, the 

 earlier authorities recommended.without exception, flowers of sulphur for use 

 in the control of surface mildews. The present tendency, however, seems to 

 be in favor of the finely ground sulphur which can be made finer than the 

 former and appear to be fully as efficient, if not more so.i 



Pulverized sulphurs produced by means of grinding are now almost 

 universally known as flour sulphur; these may or may not be bolted to insure 

 uniformity. It seems reasonable to suppose that the similarity of prepara- 

 tion of this and wheat flour may have suggested the word. Very likely the 

 similarity in sound of flour and flower may have been used to deceive the 

 consumer. Powder crude sulphur may be purchased as well as refined sul- 

 phur in all grades of fineness. 



Blown or Ventilated: The rubber industry requires an extremely fine 

 sulphur and a grade of ground and bolted sulphur is supplied to them which 

 is known as "blown" or "ventilated." A very finely ground sulphur is beaten 

 up by machinery through which passes a current of air supplied by a power- 

 ful electric fan. The very finest particles are thus separated from the coarser 

 ones. The Insecticide Laboratory has examined samples of remarkably fine 

 sulphur of Eastern production which appear to have been treated in this way. 

 These are being advertised quite extensively in the Eastern States for the 

 dusting of plants, and theoretically ought to be very efficient. They are also 

 the most suitable for the preparation of a wettable sulphur. The cost of 

 these plus the freight charges across the continent would very probably pre- 

 vent their extended use in this State unless experiments show them to be 

 much more efficient than those of local production. In communicating with 

 the local refiners, it is learned, however, that they could furnish a similar 

 quality if the demand were sufficient to warrant the installation of the 

 necessary machinery. 



USE OF DRY SULPHUR. 



The use of sulphur in one form or other antedates the earliest records 

 of man's efforts to control the insect and fungous enemies of cultivated 

 crops. The sulphur of the eighteenth century must have been a very potent 

 substance indeed, for in 1787 the following recommendation is made: "First 

 wet the trees infested with lice, then rub flowers of sulphur upon the insects 

 and it will cause them all to burst. "i The extensive use of sulphur in France 

 for the control of surface mildews of grape vines dates from about the year 

 1850, although its value for this purpose had been known long before that 

 time. To this day it remains without a formidable rival as a remedy against 

 a great variety of agricultural pests. Factors which have contributed to its 

 universal use are: its cheapness, efficiency, ease of purification, abundant 

 supply, non-poisonous nature, harmlessness to the higher animals, vegetation 

 and soils, and double utility both as an insecticide and fungicide. 



i Ibid. 



i Goeze, J. A. E., "Geschichte einiger schadlichen Insecten," Leipsig, 1787, 

 168. (Cited by Lodeman, "The Spraying of Plants.") 



