THE MONTHLY BULLETIN. 269 



to mask the presence of the other precipitates. The free sulfur is 

 believed to be the only constituent of fungicidal value, the others 

 being merely incidental to this economical manner of precipitating 

 free sulfur in a finely divided form. The iron sulfid and calcium 

 sulfate also serve to prevent the minute particles of sulfur from 

 flocculating (i. e., uniting to form coarser grains). 



From the above description, the iron sulfid being composed of 

 fairly insoluble and inert substances, it may be inferred that this ma- 

 terial nuiy be mixed with any of the arsenicals without fear of 

 materially affecting their composition. In some cases, the liability 

 of arsenical foliage injury is reported to be lessened by the presence 

 of the fungicide in question. 



Other free sulfur paste preparations. Recently there have come 

 into the market other forms of finely divided free sulfur mixed with de- 

 flocculating agents, notably "Atomic Sulphur" and "^Milled Sulphur." 

 These two preparations are composed of free sulfur ground to an impal- 

 pable powder in the presence of a small quantity of some material to 

 prevent the flocculation of the particles and enough water to form a 

 paste. Sulfur in its olcmcntary form (free sulfur) is insoluble in most 

 liquids except the alkalies and is indifferent to the intiuence of most 

 of the substances present in the various sprays. The deflocculating 

 agents are in small quantity and are believed to have no detrimental 

 effect. Being of so recent origin, and of the nature of proprietary 

 preparations, these are not included in the table. So far as shown in 

 printed reports and from personal observation, it is thought that 

 "Atomic Sulphur" and "Milled Sulphur" may be used with safety in 

 combination with the different arsenicals. 



Potassium and sodium sulfids. (Liver of sulphur, sulphide of 

 potash, soda, etc.) Solutions or fusions of sulfur, in soda or potash 

 lyes, have long been known as ctfii'it'ut fungicides and have been more or 

 less used as dormant sprays. Their causticity has prevented their 

 very wide application as a foliage spray and few attempts are reported 

 to combine materials of this nature with the arsenicals. As noted in 

 the reports that are at hand, however, the results of such combinations 

 have been disastrous, as might be expected, considering the susceptibility 

 of most arsenicals to the influence of alkalies. 



Interest in fungicides of this class has recently been somewhat 

 revived through the introduction into the state of a proprietary prep- 

 aration known as "Soluble Sulphur," offered as a substitute for lime- 

 sulfur. This preparation is very similar in composition to liver of 

 sulfur, the chief difl'erence being that the former is combined with a 

 sodium base while the latter is combined with a potassium base. 



From a consideration of the nature of the materials in question, 

 (potassium and sodium sulfids, variously known as liver of sulphur, or 

 sulphide of potash and sulphide of soda; and "Soluble Sulphur") a 

 combination spray composed of any of these sulfids and any arsenical 

 except the neutral lead arsenate would be very injurious when applied 

 to foliage. It is thought that the only possible arsenical to use with 

 these alkali sulfids is the neutral lead arsenate, and even this opinion 

 is not given with absolute certainty in the absence of definite data. 



