THE BOOK OF THE LANTERN. 141 



well to try it in the lantern first, in order that any little 

 blemish not before detected can be remedied. Any little 

 clear spot where a clear spot has no business to be can be 

 touched with India ink. If the picture is to be coloured, 

 the slide need not be so firmly bound up as one to be used 

 plain. A cover glass, separated from the photograph by a 

 paper mask, with a round, square, or cushion-shaped open- 

 ing, and fastened with one or two slips of gummed (stamp) 

 paper, is quite sufficient until the artist is ready with his 

 palette and brushes. But if the slide is to be exhibited as 

 a plain photograph, it may as well be bound together as it 

 is to remain. For this purpose we require slips of gummed 

 paper fourteen inches long by three-eighths of an inch 

 broad. The paper (black needle paper is the best) should 

 be gummed before being cut, and one sheet will provide 

 for about a hundred pictures. Mix powdered gum arabic 

 with one fourth its weight of loaf sugar, and add sufficient 

 water to make a thick mucilage. Paint the paper liberally 

 with this, and hang it up to dry. When dry it can be cut 

 into slips of the above size. 



To mount a picture, damp one of the slips of gummed 

 paper, and put it sticky side upwards on the table before 

 you. Now take a slide, duly fitted with its black mask, and 

 a cover glass, all perfectly clean and free from dust. Hold 

 the combination tightly between the fingers, and bring one 

 edge down on the end of the gummed slip. Now treat the 

 slide as a porter treats a heavy box, turn it over and over 

 along the slip of gummed paper, so that each edge will 

 take up its quantum. Now carefully fold down the edges, 

 neatly adjust the corners, and the thing is done. 



