...silica cannot be proved to be the extremely altered dfibris of Radiolaria. The direct petrographical suggestion is that they are chemical precipitates....the bottom of the ocean, similar to those well known iu volcanic regions; (2) radiolarian and other siliceous remains, which may have become entirely dissolved...

...description of the jaspers several theories of their origin are considered. The theories are as follows : (i) siliceous springs in the bottom of the ocean, similar...other siliceous remains which may have become entirely disssolved in sea water; (3) volcanic ejcctamenta which may have become similarly dissolved. The two...

...silica cannot be proved to be the extremely altered d6bris of Badiolaria. The direct petrographical suggestion is that they are chemical precipitates....entirely dissolved in sea water; and (3) volcanic ejectmenta, which may have become similarly dissolved. The last is the least probable, because we are...

...silica cannot be proved to be the extremely altered dfibris of Badiolaria. The direct petrographical suggestion is that they are chemical precipitates....entirely dissolved in sea water; and (3) volcanic ejectmenta, which may have become similarly dissolved. The last is the least probable, because we are...

...silica cannot be proved to be the extremely altered debris of Radiolaria. The direct petrographical suggestion is that they are chemical precipitates....entirely dissolved in sea water; and (3) volcanic ejectmenta, which may have become similarly dissolved. The last is the least probable, because we are...