Remarks on the Natural History of Fishes. 337 



feet of wire ; moreover the magnets produced are of a greater 

 power in proportion to tlie generating energy, than those made by 

 any other process, with which I am acquainted, 



I will 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-magnet, 

 and coohng 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 produced 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 only 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. 



Art. VII. — Remarks on the " Natural History of the Fishes of 

 Massachusetts, embracing a Practical Essay on Angling ; by 

 Jerome V. C. Smith, M. D." Read before the Boston Society 

 of Natural History, March 20, 1839. By D. Humphreys 

 Storer, M. D. 



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- 

 ciety, before ceasing from my labors. In the year 1833, a vol- 

 ume entitled " Natural History of the Fishes of Massachusetts" 

 was published by one of our number. To many persons, various 

 inaccuracies contained in that work are at once obvious ; by oth- 

 ers, 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. XXXVI, No. 2.— April-July, 18;j9. 43 



