{"id":1467,"date":"2009-10-27T11:16:28","date_gmt":"2009-10-27T11:16:28","guid":{"rendered":"http:\/\/nycphantom.com\/journal\/?p=1467"},"modified":"2009-10-27T11:16:28","modified_gmt":"2009-10-27T11:16:28","slug":"what-are-the-leads-of-pencils-made-of","status":"publish","type":"post","link":"http:\/\/nycphantom.com\/journal\/?p=1467","title":{"rendered":"What are the leads of pencils made of?"},"content":{"rendered":"<p>\nThanks to a graduate from my church, who's great knowledge led me to look up the makeup of a pencil more carefully after some discussion about flesh marks of the past during church lunch. Thanks to this <a href=\"http:\/\/pubs.acs.org\/cen\/whatstuff\/stuff\/7942sci4.html\" target=\"_blank\" title=\"What's that stuff\">article<\/a>, I am less worry about the dark mark on my right pinky.\n<\/p>\n<p>\nThere couldn't be lead poisoning, since the leads of pencils today are made of graphite (carbon) instead of lead (Pb).\n<\/p>\n<p>\nSome interesting history about graphite and lead as writing tool.\n<\/p>\n<p>\nSince both graphite and lead were used in ancient times, the yet to be identified graphite was being tought as &quot;black lead or plumbago&quot;.\n<\/p>\n<p>\n<em>In 1779, Swedish chemist Carl W. Scheele determined that black lead was actually a form of carbon; in 1789, German geologist Abraham G. Werner reportedly gave it the name graphite, after the Greek graphein, meaning &quot;to write.&quot;. Inks were already widely available and were usually applied to paper with a brush called a peniculus, which is Latin for &quot;little tail&quot;, hence the basis for the word &quot;pencil.&quot; <\/em>-- Steve Ritter\n<\/p>\n<p>\nNow graphite is mixed with clay at high temperature about 1000 Celsius, to produce smoothness and hardness.\n<\/p>\n<p>\n&nbsp;\n<\/p>\n<p>\n&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Thanks to a graduate from my church, who's great knowledge led me to look up the makeup of a pencil more carefully after some discussion about flesh marks of the past during church lunch. Thanks to this article, I am &hellip; <a href=\"http:\/\/nycphantom.com\/journal\/?p=1467\">Continue reading <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[],"class_list":["post-1467","post","type-post","status-publish","format-standard","hentry","category-technical"],"_links":{"self":[{"href":"http:\/\/nycphantom.com\/journal\/index.php?rest_route=\/wp\/v2\/posts\/1467","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/nycphantom.com\/journal\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/nycphantom.com\/journal\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/nycphantom.com\/journal\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/nycphantom.com\/journal\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1467"}],"version-history":[{"count":0,"href":"http:\/\/nycphantom.com\/journal\/index.php?rest_route=\/wp\/v2\/posts\/1467\/revisions"}],"wp:attachment":[{"href":"http:\/\/nycphantom.com\/journal\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1467"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/nycphantom.com\/journal\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1467"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/nycphantom.com\/journal\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1467"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}