Appendix. 121 



events of a similar nature, of known and unknown origin, wliich 

 are recorded in history. Some of tliese cases are witliout doubt 

 attributable to the force of cyclones on the surface of the earth ; 

 others seem to be quite traceable to the force of volcanic erup 

 tions. Under which of these two causes — for it must be accounted 

 for by one of them — the case which we are now considering is 

 to be classed, remains to be decided. 



Although at first thought one would perhaps be inclined to 

 attribute its appearance to the first of these two causes, still there 

 is much to be said in favor of either theory; and although, per- 

 haps, no conclusive theory may be decided upon, a brief mention 

 will be made of those which at once suggest themselves, and the 

 matter be thus left for disposal. 



Chemical analysis does not very materially aid in the solu- 

 tion of the problem. The presence of silica, iron, alumina, 

 manganese, etc., neither proves it to be a prairie soil, nor does it 

 prove it to be volcanic. Silica and iron and organic matter 

 form the larger proportion of ingredients; the other elements, 

 which, owing to the small amount of material for analysis, could 

 not be estimated, being present only in traces. The embrown- 

 ing of the substance by heat is due, of course, to the ferric oxide, 

 which by digestion in HCl seems to be all dissolved. 



Perhaps the solution of the problem lies in the form and 

 structure of the fibrous and hairy material, which seems to be 

 present in both samples. That some of this is extraneous matter 

 which, either floating in the atmosphere, was taken up by the 

 falling snow, or derived from the atmosphere in which it was 

 evaporated, there can be no doubt. Prof. Harrington, on exam- 

 ining this fibrous material microscopically, was inclined to the 

 opinion that in it were to be detected artificial fibres, probably 

 cotton fibre ; but it is quite possible that this, if present, might 

 originate in the causes above mentioned, or perhaps from the 

 paper in which the powder was wrapped. The appearance of 

 these fibres does not show growth of any nature. Most of them 

 appear to be long, hollow and quite regular tubes, with, of couise, 

 a more or less quantity of earthy matter attached to them. In' 



