今天看到了這個精美的葉片肖像畫，覺得很有意思，找時間自己做一個。
‘Starch picture’ of Dr Jan Ingen-Housz on a geranium leaf (prepared by William Ruf and Howard Gest). The image of Ingen-Housz consists of photosynthetically-produced starch granules, which were ‘developed’ by staining with I2-KI. An engraving of Ingen-Housz (in Reed 1949) was photographed, and the negative placed in a slide projector. Light passing through the negative was focused on a geranium leaf (depleted of starch by prior incubation in darkness) for about one hour. After extraction of pigments from the leaf with boiling 80% alcohol, the blanched leaf was flooded with I2-KI solution to stain the starch granules. Within minutes, the details of the engraving dramatically appeared on the leaf. The inscription at the bottom refers to Dr Ingen-Housz’s fame as a ‘smallpox inoculator’. The ‘starch picture’ procedure was invented by Hans Molisch in 1914. Further details and an English translation of Molisch’s paper ‘On the production of photographs in foliage leaves’ can be found in Gest 1991.1。
在天竺葵葉片上通過澱粉顯色刻畫的荷蘭科學家英格豪斯博士肖像畫。英格豪斯的肖像由光合產生的澱粉顆粒組成，通過澱粉遇碘變藍的原理進行顯色。先將天竺葵在黑暗中預先培養使澱粉耗盡。再把英格豪斯照片的底片放在投影儀上，投影儀的光聚焦在暗處理過的天竺葵葉片上約一個小時。用煮沸的80%酒精提取這片天竺葵葉片的葉綠素，再加碘液顯色即可。