222 T. §. Hunt on Ophiolites. 
crystalline spar. A fibrous coating is sometimes apparent in the 
joints of the rock. Its hardness is about 4. When reduced to 
Wwas:-— 
ilica, - - - - - : - 4320 
Magnesia (by difference), - - — . 3611 
Protoxyd of iron with nickel, - . : - $829 
Water, - . - - - - - 12°40 
100:00 
The dolomite dissolved, gave for 100 parts :— 
Carbonate of lime, - . - - - - 4958 
agnesia, - - - - - 46:32 
# “ iron with manganese, - : - tae 
100°00 
average specimen of the conglomerate was pulverized - 
examination. ‘he powder effervesced even in the cold, wit 
acetic acid, which with the aid of heat, took up by prolonged 
digestion, twenty per cent of carbonates of lime and mae 
and 0-2 of oxyd of iron. The soluble portion contained car 
nate of lime 88°30, carbonate of magnesia 11°70. The residue 
from acetic acid effervesced slightly with warm dilute nitric ean 
and the solution was found to contain a quantity of magne) ' 
iginal mass (11°70 per “4 
but no lime, the whole of that base poe 
been removed by the acetic acid. The residue from the act! 
of mine acid, was decomposed by fusion with carbonate of 
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