{"id":1779,"date":"2014-04-29T10:09:21","date_gmt":"2014-04-29T14:09:21","guid":{"rendered":"http:\/\/www.ttgnet.com\/journal\/?p=1779"},"modified":"2014-04-29T10:09:21","modified_gmt":"2014-04-29T14:09:21","slug":"tuesday-29-april-2014","status":"publish","type":"post","link":"https:\/\/www.ttgnet.com\/journal\/2014\/04\/29\/tuesday-29-april-2014\/","title":{"rendered":"Tuesday, 29 April 2014"},"content":{"rendered":"<p><span style=\"font-weight: bold; color: #000099; font-family: Arial;\">10:05 &#8211;<\/span><span style=\"font-family: Arial;\"> Among other things yesterday, I filled and capped several hundred bottles for biology kits. I&#8217;ll do several hundred more today.<br \/>\n<\/span><\/p>\n<p><span style=\"font-family: Arial;\">First up is Seliwanoff&#8217;s Reagent Part A, which is simply a dilute solution of resorcinol (AKA 1,3-dihydroxybenzene or <em>m<\/em>-dihydroxybenzene). I had two liters made up, but I didn&#8217;t like the looks of it. When I made it up some time ago, it was colorless, indiscernible from water. It now has a very pale tan cast. Upon reflection, I realized that the <a href=\"http:\/\/en.wikipedia.org\/wiki\/Dihydroxybenzene\">other two isomers<\/a> of this chemical, 1,3-dihydroxybenzene (AKA catechol or pyrocatechol) and 1,4-dihydroxybenzene (AKA hydroquinone), are both used in developers for silver halide black-and-white film and paper. As anyone who&#8217;s done black-and-white darkroom processing will remember, film and paper developers oxidize and turn brown as they age.<br \/>\n<\/span><\/p>\n<p><span style=\"font-family: Arial;\">So I did a quick check and found that the Seliwanoff test worked properly with the tannish solution. Still, better safe than sorry, so I disposed of the aging solution and made up fresh.<br \/>\n<\/span><\/p>\n<hr style=\"width: 65%; height: 3px; font-family: Arial;\" \/>\n","protected":false},"excerpt":{"rendered":"<p>10:05 &#8211; Among other things yesterday, I filled and capped several hundred bottles for biology kits. I&#8217;ll do several hundred more today.\n<\/p>\n<p>First up is Seliwanoff&#8217;s Reagent Part A, which is simply a dilute solution of resorcinol (AKA 1,3-dihydroxybenzene or <em>m<\/em>-dihydroxybenzene). I had two liters made up, but I didn&#8217;t like the looks of it. When I made it up some time ago, it was colorless, indiscernible from water.<\/p>\n<p> <a href=\"https:\/\/www.ttgnet.com\/journal\/2014\/04\/29\/tuesday-29-april-2014\/\">&nbsp;&raquo;&nbsp;Read more about: Tuesday, 29 April 2014 &nbsp;&raquo;<\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[11],"tags":[],"class_list":["post-1779","post","type-post","status-publish","format-standard","hentry","category-science-kits"],"_links":{"self":[{"href":"https:\/\/www.ttgnet.com\/journal\/wp-json\/wp\/v2\/posts\/1779","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.ttgnet.com\/journal\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.ttgnet.com\/journal\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.ttgnet.com\/journal\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.ttgnet.com\/journal\/wp-json\/wp\/v2\/comments?post=1779"}],"version-history":[{"count":0,"href":"https:\/\/www.ttgnet.com\/journal\/wp-json\/wp\/v2\/posts\/1779\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.ttgnet.com\/journal\/wp-json\/wp\/v2\/media?parent=1779"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ttgnet.com\/journal\/wp-json\/wp\/v2\/categories?post=1779"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ttgnet.com\/journal\/wp-json\/wp\/v2\/tags?post=1779"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}