58 
in which the nodule and the matrix are of different materials. 
The present structure would appear to have been produced 
by the ejection of the trap in a fluid state under the sea; 
masses of which, cooling in their passage, fell again into the 
liquid bed, and being enveloped, were heated nearly to the 
temperature of the mass, and so adhered without losing 
their outline. Where several fell together, and were exposed 
to subsequent pressure, they would present the flattened 
appearance before described; and when more deeply en- 
veloped, and thus subjected to a higher temperature, the 
nodular structure would again vanish by their complete 
fusion. 
It is even conceivable that the most capriciously varied 
parts of this and other trap rocks may owe their origin 
to the soldering together of nodules of heterogeneous matter, 
projected from different depths, or at different times, or 
subjected to successive coolings and heatings. 
Professor Kane read a paper entitled ‘‘ Researches on 
the Compounds derived from Pyroacetic Spirit.” (Second 
Series.) 
When dry chlorine gas is passed into pure mesitylene, 
C,H, muriatic acid is given off, and a compound body, 
solid, in white prismatic crystals, is formed, giving on analysis 
the formula c,n, cl. A yellow substance obtained by the 
action of iodine on nascent mesitylene, but in too small 
a quantity for analysis, is considered to be c, H,I- 
When mesitylene is treated with nitric acid, copious red 
fumes are given off, and a very heavy thick fluid obtained, 
which gives on analysis the formula c,H,0,- This fluid ab- 
sorbs ammonia, and forms therewith a compound soluble in 
water, and giving with most metallic solutions insoluble pre- 
cipitates. 
If pure mesitic alcohol be heated with nitric acid, there is 
