Analysis of the Maryland Aerolite. © 18h 
and the power necessary for its successfuljoperation, are not 
greater than is required by power jennies doing the same 
work. A frame of 300 spindles will spin 300 runs, 1600 
yards to the run, per day, and will with ease turn off 100 Ibs. 
of four run yarn in twelve hours. ‘Two girls of sixteen years 
of age, will attend a three hundred spindle frame one on each 
side. 
Ast. XVIII.—Analysis of the Maryland Alerolite. By 
Georce Cuitton, Lecturer on Chemistry, &c.® 
Tue piece of Maryland erolite subjected to examination, 
weighed 228.30 grains in air, and lost 62.25 grains by im- 
mersion in water, at 60° temperature. Its specific gravity is 
therefore, 3.66. The external crust was taken off, and the 
remainder powdered, not very finely, and separated into two 
parts by the magnet ; 40 grains were obedient to the magnet, 
25 of which were taken for examination. The same quan- 
tity was taken of the unmagnetical portion. ue 
Examination of the unmagnetical portion of the Marglamd 
Aerolite. 
Process 1.—The 25 grains were digested in dilute nitric 
acid; an undissolved part floated, which, together with the 
solution, was decanted from a heavier part, which remained 
at the bottom of the flask. Too this last, muriatic acid wag 
added, and digestion continued till every thing soluble was 
taken up. The two insoluble parts managed in the usual’ 
way, and carefully dried, weighed 15.87 grains. During 
exposure to a red heat, in a crucible, sulphur burnt off with 
its usual blue flame, and left siliceous earth which weighed 
14.6 grains. 
Process 2.—-The acid solutions were mixed together and 
evaporated slowly to dryness; during which portions of 
* A notice of the fall af this zrolite was published in our last number, 
see Vol. IX. p. 351. For amore particular description of the stone, 
and for illustrative remarks respecting it, See the end of this paper.—Ep. 
