fein, 
Remarks on the Natural History of Fishes. 337 
feet of wire; moreover the magnets produced are of a greater 
power in proportion to the generating energy, than those made by 
any other process, with which I am acquainted. 
Twill here mention an experiment which I have tried in com- 
mon with others, of making magnets by attaching red hot pieces 
of steel to an artificial magnet, or to the temporary electro-maguet, 
and cooling them suddenly. 
To an artificial magnet capable of sustaining eight pounds, I 
applied a piece of ignited steel weighing one ounce, semicircular 
in form, and immersed it in water ; it was found capable of sus- 
taining three ounces, only about one fortieth of the power used, 
and in no experiment, although many were made, was the ratio 
between the preduced and the producing powers greater. 
The reason of this great disproportion appears to be, that when 
the metal is raised to a red heat, magnetism is not easily induced 
in it, and that it is ouly when it arrives at a lower temperature 
in the cooling process, that it receives that magnetic virtue which 
it retains, and this no doubt also accounts for its inferiority to. the 
first method mentioned—for there the galvanic fluid is made to _ 
circulate around the steel : and the current of the magnetic fluid 
is also. kept continuous by the soft iron uniting the two poles. 
—S— 
Arr. VII_— Remarks on-the “ Natural History of the Fishes of 
M assachusetts, embracing a Practical Essay on Angling ; by 
Jerome V. C. Smiru, M. D.” Read before the Boston Society 
of Natural History, March 20, 1839. By D. Humpureys 
Srorrr, M. “ 
My report upon the Fishes of our State having been presented 
to the chairman of the Zoological Commissioners, I feel that, as 
their ichthyological curator, a duty is expected of me by this so- 
lety, before ceasing from my labors. In the year 1833, a - 
ume entitled “ Natural History of the Fishes of Massachusetts 
Was published by one of our number. To many perenne; ae 
itaccuracies contained in that work are at once obvious ; by ot - 
ets, who have a slighter acquaintance with natural history, all is 
Supposed scientific and true; while if errors really exist, it is cer- 
tainly the duty of some one-to correct them. I have thought it 
Vol. xxxvz, No. 2.—April-July, 1839. 43 - 
