144 Description of a new species of Dory. 
ponding male screw, is fitted. The perforation in this cylirt- 
der, forms a continuation of that in the ball, but narrows 
low, and ends in a small hollow cylinder of platina, which 
. 
between the cavities in the two balls. 
(NN) in the vertex, the orifice of the central tube may be ad- 
justed to a proper distance from the external orifice. Three 
different cylinders, and as many central tubes, with platina 
orifices, of different calibres, were provided, so that the flame 
might be varied in size, agreeably to the object in view. 
I have always deemed it best, to transmit the oxygen gas 
through the tube in the axis ; since two volumes of the hy- 
drogen, being required for one volume of oxygen, the larger 
tube ought to be used for the former: and the jet of hydro- 
gen is placed between a jet of oxygen, within it, and the at- 
spheric air without. 
nder the table, is a gallows, (G) with a screw for attach- 
ing a pipe, leading from a self-regulating reservoir of hydro- 
gen. 
ArT. XIII.—Description of a new species of Dory, called 
the crinited Zeus, from Block cad ; of! communica- 
tion from Samue. L. Mrrcninti, LL. D. of New-York, 
to Aaron C. Witiey, M. D. of New-Shoreham ; dated 
March 17, 1826. (With a figure.) 
My Dear Sir, 
To me, as to yourself and your 
neighbours, it seems an individual of a species, not before 
observe =e does not belong to either of the three sorts, 
» mm strong and striking points, from that sent me, 
not long ago, by Mr. Vernon, of Newport. 
