SicT. in.] Magnetism. 39 



solved. In the mean time, the ingenuity, zeal, 

 and perseverance, evinced in Mr. Churchman's late 

 publications on this subject, deserve the attention, 

 the thanks, and tiie encouragement of the j^inloso- 

 phic world*. 



Many other writers, of acknowledged scientific 

 eminence, have distinguished themselves by new 

 experiments, and ingenious hypotheses on mag- 

 netic attraction, within the period of which we 

 are speaking. Among these may be mentioned 

 Muschenbroeck j", Whiston, Celsius J, van Swiu> 

 den, Lambert §, Euler||, Knight ^f, Mitchel, Can- 

 ton, and Cavallo. To detail the opinions enter- 

 tained, and the facts successively brought to light 

 by each, would far exceed our prescribed limits. 

 But, after all the inquiries of these philosophers, 

 it must be acknowledged that " clouds and dark- 

 ness rest" upon this part of science ; that even its 

 general principles are little understood; and that 

 we are yet far from being furnished ^vith materials 

 for a satisfactory system on the subject. Perhaps 

 another century may accomplish this, which, when 



* See Churchman's Magnetic AtluHy 4to, 3(lt?clitlon, 1800. 



f Dissert. Phj/sico-Experijuenlalis de Magncte. 



X Tentamina Magnetica, 4to. Also Manoirs on the Analogy hc- 

 twecn Elect, and J^Iag. 3 vols, 8vo, 1/85. 



§ The experiments and calculations of M. Lambert, on the 

 fiolarity and variations of the magnetic needle, deserve particu- 

 lar attention. He was a very accurate and sagacious philusij- 

 pher. See the Memoirs of the Academy of Ikrlin, for 1/ JU, pub- 

 lished in 1758. 



II Euleri Opitscula, torn, iii, conlinens Thcoriam Magnctis, Ber- 

 lin, 1751. 



% An Attempt to explain the Fhenomcna of yadirc hy Tso Prin- 

 ciples, ^x'. 4 to, 1748. 



