8o 



THE OREGON NATURALIST. 



LEAF PRINTING. then it is ready for use. 



A substitute for a printing frame may be 



The study of leaves is at once one of the made of any smooth board of suitable size, 

 most important and interesting departments of Place the paper, sensitized side upward, on the 

 Botany, their infinite variety of color, form and board, lay the leaf to be printed upon that and 

 venation affording an inexhaustable fund of cover it with a piece of glass of the same size as 

 entertainment and instruction, the board Fasten the glass and board together 



The leaves must be seen and studied as they by attaching a conimon v;lothes pin to each end 

 grow in bewildering multitudes and in apparent- ^d place it in the sun. 



ly endless variety and they must be gathered After it has been exposed to the sunlight a 

 and compared that the order which prevails in sufficient length of time take out the paper 

 their confusion may be traced and that the and wash it in an abundance of clean water, 

 system may be found in their resemblances and Wherever the jxiper has been exposed to the 

 differences. It is useful to preserve the leaves direct sunlight the dye will have become "fast" 

 thems.'lves for reference, for comparison and as and the paper will remain a dark blue, while 



mementoes, and the skeletonizing of leavas is 

 also an excellent practice. Still another way 

 of studying leaves, not to take the place of the 

 methods I have mentioned but to supplerjient 

 them, is by making photographic leaf prints. 



in the spot shaded liy the leaf the coloring will 

 wash off leaving the paper white, showing the 

 white print of the leaf on a blue background. 



If the exposure has been sufficiently long all 

 the details of the leaf structure will be accurate- 



No expensive materials are necessary for no ly and beautifully printed in, but if the sun has 



camera is required, the leaves themselves being not had time to do its work thoroughly the 



used as neg.atives and the print being made lighter shades of color will be entirely washed 



directly from them upon the sensitized paper. out, the venation disappear and the print show 



Instead of using the paper employed in only in outline, 



ordinary photography it is the best to us; ferro- The thickness and opacity of leaves varies as 



in-ussiate paper and make blue prints, these greatly and the sunlight has so many degrees 



being much cheaper and far easier to make, of brightness that no rule can be given as to the 



while they are quite as satisfactory as the costly e.xact length of time necessary in exposing a 



gold-toned salt of silver prints. p,int. The beginner must experiment and 



If you wish to prepare your own paper take learn to use his own judgment. It will be 



one ounce each of ferroprussiate of potash, and 

 of citrate of iron that has been neutralized with 

 ammonia, and dissolve them in one half pint 



found a great convenience if the board useti as 

 a printing frame is made of two pieces fastened 

 together by a hinge so that one end may be 



of water. This will make a rather thick dye folded back and the pajier examined to ascertain 



which must be kept in a stone bottle, or if in a how fast the printing is going on. 



glass bottle must be carefully wrapped to ex- f have frequently prepared my own paper in 



elude the light. the manner described but I find it much more 



In the evening by a dim lamp light pour out convenient and almost as cheap to buy ferro- 



a little of this dye in a saucer and with a prussiate paper of some dealer in photographer's 



feather or flat brush spread it over your paper, supplies. The usual cost, postage included, 



which should be stiff and unruled. The is three cents for two dozen leaves, size 4x5 



sensitized surface will appear of a dirty yellowish inches. 



hue, giving but little promise of the rich blue It has been my practice to mount prints on 



which it is to assume, for ^he dye needs direct cheap white cards, writing the name of the 



sunlight to make its real color appear. Put the order to which each specimen belongs at the 



paper away in a dark place until it is dry and top of the card and the generic and specific 



