360 J.D. Dana on the Consolidation of Coral Formations. 
portions larger than this, it would be precipitated whenever separ- 
ated. e two statements would therefore seem to a chemist to 
be very much of a kind, if not identical,—unless it is meant that 
more than one part of the hydrate to 778 of water would never 
be separated. 
We pass to the chemistry of the passage which is the important 
point in the whole discussion,—for if false, the theory proves 
to be no better in its principles, than in its alleged facts. 
Now it is well known that ammonia will neither separate, nor 
precipitate, soluble or insoluble hydrate of lime, by action on the 
dissolved sulphate; on the contrary, sulphate of ammonia is 
readily decomposed by a salt of lime, or by its hydrate. What 
avails then the long array of facts and arguments with which 
Prof. Horsford fills up his paper? Much might be brought for- 
ward on other parts of his chemical discussions, but as the key- 
stone of his theory is gone, it would be a waste of words.* 
VII. Prof. Horsford repeats from his former paper another mode 
of consolidation, viz., “The deposition of finely powdered car- 
bonate of lime, with mucilaginous matter filling up the interstices 
between the grains of rock, and serving to increase the cohesion.” 
This idea of making rocks by sticking the particles together with 
mucilage, (or with glue, as is implied in another place,) is quite 
original with Prof. Horsford. It needs no discussion. 
VIIL. After going over, with many details, the prominent points 
in the theory of consolidation proposed by him, Prof. Horsford 
presents another view which was barely intimated in his former 
Paper, and which falls in with the theory that I had been led to 
ado 
proportion, so asto be able to dissolve some carbonate of lime, a 
in time, produce the consolidation. With reference to submerge 
deposits, the same principle was supposed to operate ; but ast ere 
* Prof. Horsford insists in his article upon a certain order of decomposition, which 
is necessary to his theory ; sulphuretted hy i 
or an ammioniacal salt the later. Facts in nature are the reverse of 
