New Electro-Magnetic Engine. 131 
lated or cowled in a very peculiar manner. The centre of the 
flower is yellowish and maculate; the laminz of the petals blue. 
NemostyLes cemmirtora, Nuttall, in Trans. Philad. Phil. Soc. 
Flowers a beautiful blue an inch or more in diameter. Found 
by myself in the vicinity of Fort Towson, western Louisiana, 
eastern Texas, and the prairies of Alabama near Demopolis, as 
long since as the year 1821. Both species are beautiful plants, 
belonging to the natural order Iride. 
You will perceive my object in the details of this communica- 
tion. It is— 
Ist. The description of new and unknown plants. 
2d. Additional memoranda relating to those that are rare and 
little known. 
3d. To enlarge the knowledge of the range of certain plants. 
Waterbury, Ct., May 5, 1845. 
Arr. XIV.—New Electro-Magnetic Engine; by Cuas. G. Pace, 
M. D., Professor of Chemistry and Pharmacy, Columbian Col- 
lege, Washington, D. C. 
T'u1s new species of electromotion, which by way of distine- 
tion I denominate the axial reciprocating engine, was unsuccess- 
fully attempted in the year 1838, and notice made of it in 
this Journal, Vol. xxxv, for 1839, pp. 261 and 262, together 
With some other experiments upon the interior of helices. My 
failure at that time was owing to a want of suitable batteries, 
but being furnished in the winter of 1843-4, with some of the 
excellent batteries of Prof. Grove, I recommenced the experi- 
ment, and exhibited one of these interesting engines to the mem- 
bers of the Geological Association held in this place in May, 
1844, To sustain a small needle within the helix is a trite ex- 
periment, but by the arrangements I have adopted, a bar of soft 
iron or of steel (which becomes instantly and powerfully mag- 
netized) is sustained entirely free from any visible support, and 
this too by the action of only six small Grove’s batteries. This is 
almost a realization of the fable of Mahomet’s coffin, or the statue of 
Theamides. When the helix is connected with six pairs Grove’s, 
in good action, it will draw up within its centre a bar of iron or 
steel weighing two or three pounds, and sustain it with its upper 
