Warning: Undefined array key "visitor_referer_type" in /var/www/vhosts/wordinf.com/core/app/libraries/Core.php on line 98 William Gilbert (astronomer) - Gilbert does not seem...
Gilbert does not seem to have known that there were any other bodies than iron or the lodestone that possessed magnetic properties; for he called particular attention to the fact that all other substances that possessed magnetism to some degree owe their power to the presence of iron in some condition or other.