G. Child on the production of Organisms in closed vessels, 381 
have expected similarity in this respect between the brachiopod 
Leptena and the Conchifers, Ostrea and Mytilus, all three having 
the two-valved structure. The presence of a much larger 
amount of organic matter in the two latter than in the univalve 
Litorina seems to show that the relative abundance of animal 
substance in the shell is essentially connected with the two- 
valved structure; if so, we must probably conclude that the = 
tena had been mineralized at the expense of a considerable 
the recent molluscous shells, The fossil occurs in limestones, 
slates, schists, and sandstones, but I have no record as to the 
matrix of the specimen analyzed. 
The carboniferous limestone compared with the foregoing is 
& specimen of the Lower Carboniferous marine formation of 
Windsor, N. S.; it is made up to a great extent of shells among 
which brachiopods are abundant. It gave on analysis: 
Carbonate of lime, —- - - aoe - 97-64 
Carbonate of magnesia, - - - : mere. 
Sesquioxyd of iron, - - - . - 07 
y, sand, and silica, . - - . - 068 
Phosphoric acid, - - - trace 
99°49 
Here we may note the absence of organic matter and the addi- 
tion of a little magnesia, introduced, no doubt, by the actions 
of sea-water. Had the investigation, of which the foregoing 
will indicate to some extent the design, been carried on, many 
interesting results would no doubt have been obtained. 
Art. XLVII.—Ezperiments on the Production of Organisms in 
Closed Vessels; by GEORGE CHILD, M.D.’ 
THE researches, an account of which is contained in the fol- 
lowing paper, are in continuation of those which, through the 
indness of Prof. Phillips, I had the honor of communicating 
to the Royal Society in May last, and of which an abstract ap-— 
peared in the ‘Proceedings’ for June 16, 1864. The former 
series of experiments did not pretend to be, in any respect, com- 
lete. Those which gam now about to describe will, I hope, be 
considered to be more so in regard to one main subject of the 
inquiry ; but they also suggest further researches upon some 
collateral branches of it, which I hope to find time and oppor- 
unity to prosecute. In the former series I experimented with 
animal substances mixed with water and enclosed in glass bulbs 
? From the Proceedings of the Royal Society for April 27, 1865, p. 178. 
