VOL. I.] PHILOSOPHICAL TRANSACTIONS. 140 



He exhibits also the arteries, nerves, and veins, dispersed through this 

 medulla, and inquires. Whether the nerves proceed from the medulla itself or 

 its meninx ? and discourses also of the principle and distribution of the nerves ; 

 referring for ampler information, in this and the other particulars, to that ex- 

 cellent book of the learned Dr. Willis, De Anatome Cerebri. 



END OP VOLUME FIRST OP THE ORIGINAL. 



Of a considerable Loadstone dug out of the Ground in Devonshire^ 

 By Dr. Edw. Cotton. iV''23, p. 423. Vol. ii. 



This stone weighs 6o pounds ; and though it takes up no great weight, yet 

 it moves a needle about nine feet distant. A part which had been broken off he 

 has sent up also, because when put in its proper place, it adds much strength 

 to it, but without that addition it moves not much more than at seven feet 

 distance. 



Remarks on Load-stones and Sea Compasses. By Mr. Oldenburg, 



N' 23, p. 423. 



A noble person, on a late occasion, affirmed that a needle of a sea compass, 

 put in a good iron mine, which yielded 23 pounds of metal out of 120 

 pounds of ore, was not sensibly moved by it. 



Another honourable person desired it might be observed whether touched 

 needles move otherwise, when the veins of iron do not lie north and south, 

 than when they do ? 



It being inquired from abroad, whether sea compasses in England were 

 brought to greater perfection than in other countries ? Answer was made by 

 intelligent persons here, that all the perfection of our sea compasses as yet 

 consisted in this, that the needles be touched by good load-stones and 

 well balanced, and that the variation be truly placed : though it was suggested, 

 that for the greater perfection of such sea compasses, a way was contriving to 

 show the variation to minutes and seconds. 



It was also proposed, that it might be inquired into, 



1 . Whether a needle may be so touched on any magnet, as not to point 

 to the true north and south, to be tried in such places where there is no vari- 

 ation known ? 



2. Whether different load-stones will give different directions ? And whether 

 fainter or stronger touches on one and the same magnet will cause any varia- 

 tion in the directions ? For which purpose as many load-stones should be pro- 



