“钍的放射性的简易实验”在今年四月号“物理通報”發表後,我們又用汽灯软纱罩作了兩個不同的实驗(软纱罩可由汽灯行或電料行購取,現價每個四角左右)。一、钍的放射線使照像膠片感光軟紗罩含有硝酸灶[Th(NO_3)_4],钍和它蛻變後產生的女元素和以下幾代女元素放出的α,β,γ三种射線,都能使照像乳膠感光。我們在暗室中放软纱罩聚貼膠片的感光面,再用黑紙黑布包好,放置一個月(5月20日至6月20日)拿出沖洗,底片上有很清晰的纱罩形象,洒洗出來的正片如附圖。估計放置半個月就可 “Thorium radioactivity experiment” After the publication of the “Bulletin of Physics” in April this year, we made two different experiments with the soft light gauze of the lamp (the soft gauze can be bought by a vapor lamp or an electrical material counter at the current price per square corner about). First, the thorium radiation to make photographic film Sensitive soft gauze containing nitric acid stove [Th (NO_3) _4], thorium and its transformation after the female element and the following generations of female elements released α, β, γ three rays can So that photographic latex sensitive. We put the soft cover in the darkroom polygamy photosensitive surface, and then black paper bag wrapped, place a month (May 20 to June 20) out of the washing, the film has a very clear image of the mask, Sprinkle out the positive as shown in the photo. Estimated to be placed for half a month can be