54 Kansas Academy of Scieiice. 



In sampling, small quantities were taken from difiPerent parts of 

 the vat: these were well mixed and a subsample taken for analysis. 

 Care was taken to start the determinations immediately after 

 sampling. 



The diluted dips are of an orange-red color. On standing ex- 

 posed to the air an incrustation soon forms, which consists of 

 calcium carbonate and free sulfur. If this incrustation is broken 

 it falls to the bottom of the containing vessel and a fresh incrusta- 

 tion forms. A slight jarring or even a breath of wind is sufficient 

 to break up this crust ; so after standing for some time there will 

 be a layer of sediment on the bottom of the vessel as well as a crust 

 on top, both being of the same chemical composition. 



Qualitative analysis of the dip showed presence of calcium sul- 

 fides, polysulfides, and thiosulfate. At all times hydrogen sulfide 

 was evolved, due probably to the action of the atmospheric carbon 

 dioxide on the sulfide. 



If sulfites and sulfates were present they were in such slight 

 amounts as would be negligible. The absence of quantitive 

 amounts of the last two was somewhat surprising, as it is well 

 known that thiosulfates in solution are converted slowly to sulfites 

 and sulfates according to these reactions : 



CaSsOa = OaSOs + S. 

 CaS03 + 0=-CaS04. 



If this decomposition and oxidation takes place in the dip at all 

 it takes place very slowly. 



To the writer's knowledge there is no method known for separat- 

 ing the polysulfides of calcium. An attempt was made by employ- 

 ing a freezing mixture of snow and calcium chloride and partially 

 freezing the concentrated ooze, as the dip is called before diluting. 

 The chemical composition of the frozen and the unfrozen portions 

 showed, however, that little or no separation was accomplished. 



Necessarily, then, the determinations were limited to those of 

 total sulfur, total calcium, and calcium thiosulfate. By subtracting 

 the calcium and sulfur calculated from the percentage of the thio- 

 sulfate from the total calcium and sulfur, percentages were obtained 

 which represented, approximately at least, the calcium and sulfur 

 existing in the combined sulfides. In no case in a large number of 

 analyses of dip did this percentage correspond to that of any one of 

 the polysulfides. Usually it fell between the tetrasulfide and penta- 

 sulfide, and could always be assigned to a mixture of the mono- and 

 the pentasulfide. This will be spoken of later in the paper. 



