...the profile of an object, thus obtained, must of course be preserved in an obscure place, for all the attempts that have been made to prevent the uncoloured parts of the copy from being acted upon by light, have hitherto been unsuccessful. They have been covered with a thin...

...the profile of an object, thus obtained, must of course be preserved in an obscure place, for all the attempts that have been made to prevent the uncoloured parts of the copy from being acted upon by light, have hitherto been unsuccessful. They have been covered with a thin...

...microscope could be copied on prepared paper without difficulty. We also learn the fatal fact, that ' no attempts that have been made ' to prevent the uncoloured...upon by light, have as yet been successful.' They had discovered but half the spell ; the pictures could not be fixed. The agency they had invoked continued...

...but in this case the exposure should be only for a few minutes : by the light of candles or lamps, aa commonly employed, it is not sensibly affected. No...have as yet been successful. They have been covered by a thin coating of fine varnish, but this has not destroyed their susceptibility of becoming coloured;...

...speedily become dark. The copy of a painting (paintings in glass were employed in these experiments) or the profile, immediately after being taken, must...being acted upon by light have as yet been successful Besides the applications of this method of copying that have just been mentioned, there are many others...

...permanent. The copy of a painting or the profile, immediately after being taken, must be kept in an obsctire place; it may, indeed, be examined in the shade, but...have as yet been successful. They have been covered by a thin coating of fine varnish, but this has not destroyed their susceptibility of becoming coloured;...

...this case it is more readily acted en than when paper is used. After the colour has been once fixed on the leather or paper, it cannot be removed by the...have as yet been successful. They have been covered by a thin coating of fine varnish, but this has not destroyed their susceptibility of becoming coloured...

...this case it is more readily acted on than when paper is used. After the colour has been once fixed on the leather or paper, it cannot be removed by the...have as yet been successful. They have been covered by a thin coating of fine varnish, but this has not destroyed their susceptibility of becoming coloured...

...this case it is more readily acted on than when paper is used. After the colour has been once fixed on the leather or paper, it cannot be removed by the...have as yet been successful. They have been covered by a thin coating of fine varnish, but this has not destroyed their susceptibility of becoming coloured...

...but in this case the exposure should be only for a few minutes ; by the light of candles or lampa, as commonly employed, it is not sensibly affected....covered with a thin coating of fine varnish, but this lias not destroyed their susceptibility of being coloured ; and even after repeated washings, enough...