Origin of Flint. 173 



often associated with these amoi'phous varieties, and in some beds of 

 sandstone which are made up entirely of small crystals of quartz." 



Professor John Brainerd, at the meeting of the American Associa- 

 tion for the Advancement of Science, at Cleveland, in 1860, took the 

 same ground in relation to the formaticni of some sand rocks, and also 

 attributed the origin of the quartz pebbles of the sandstone conglom- 

 erate to the same cause, instead of water detrition. His theory was 

 not then adopted, although he presented some irrefutable facts and 

 ingenious arguments in support of his position. 



Waters must be highly charged with silica if they hold in solution 

 all the material that is apparently laid down by them in the form of 

 crystalline sandstone, silex pebbles, beds of flint, elc. The decay of 

 vegetable matter, containing minute proportions of silica, may contrib- 

 ute, in some degree, but that would leave a large proportion to have 

 been dissolved from previously formed siliceous rocks, if that is the 

 only source from which it can be derived. 



Ever since the days of Homer, history tells us that blood rains have 

 fallen from the heavens, filling men's hearts with fear and awe of some 

 mysterious power that ruled or raged above them. But science, of a 

 comparatively recent date, has allayed our fears, by determining that 

 the reddish dust which, accompanied with ram, produces the blood- 

 showers, are to a great extent made up of microscopic atoms, mole- 

 cules or organisms, many of them of a siliceous character, the color 

 being due to the presence of red oxide of iron. These showers are 

 sometimes of immense extent. One is described as covering an area 

 of more than a million of square miles ; another covering two hundred 

 square leagues, and making an earth deposit of an inch in thickness, 

 or equal to 16,000 cubic feet to a square English mile. Xo discovered 

 fact or well digested theory accounts for the origin of these showers, 

 or what relation they may hold to some unexplored deposits that have 

 been observed. And if they can not be traced to a terrestrial origin, 

 do not they suggest the probability of being generated, collected, and 

 precipitated from that great laboratory, the atmosphere, or in obedience 

 to some law of the universe evolved beyond that even, as in primeval 

 creation, and that some corresponding accumulation has been showered 

 into the carboniferous sea whei'e these flint specimens were formed, 

 enveloping its organisms and assuming the crystalline and varied forms 

 that are now presented to us. Ehrenberg, who carefiilly studied this 

 phenomena of "blood-showers," wonderingly asks: '"How many 

 thousand millions of hundred-weight of micjfgscopic organisms have 

 fallen from the heavens since the period of Hotaer?" But if we would 

 look back to the period when the cause and effect of this phenomena 



