The Miceoscope. 153 



built up of a double row of these vertical, elongated "palissade 

 cells." 



Catha Edulis is a glabrous shrub or tree, widely distributed in 

 the interior of eastern Africa, from Abyssinia to Port Natal, and is 

 largely cultivated throughout these regions, and also in the southern 

 districts of Arabia. The leaves yield an alkaloid which has been 

 denominated, provisionally, Katine. 



Dkawings for Process Work. — Benjamin Day gives 

 some excellent hints in the Scientific American in regard 

 to drawing for process work. Every microscopist should 

 know not only how to draw, with and without the camera lucida, 

 but also how to draw so that his work can be reproduced for 

 illustration; the suggestions here offered will be found of value. 

 Mr. Day says: Drawings for process work are made on all kinds 

 of Bristol-board, ledge paper, Whatman's drawing paper, grained 

 drawing papers, such as Steinbach's, Day's grained, enameled, 

 printed and embossed cards, photographic paper, plain Saxe or 

 Clemen's leatherized, and heavy-coated enamel papers, such as Day's 

 Scotch board. The implements used for coarse work are ordinary 

 writing pens and for fine work Gillots' map pens, Crowquills' No. 

 290, Somerville lithographic pens, and Keuffel and Esser's litho- 

 graphic pens. Some of the most beautiful line work can be drawn 

 with a brush, such as is used by miniature painters, viz. : red sable 

 No. or No. 1, if it is trimmed down until but eight or ten hairs 

 are left to form a point. There are all kinds of ready-ground drawing 

 inks in the market, but none so good as freshly ground India ink, 

 which can be ground readily, perfectly and absolutely black, in an 

 ordinary saucer, and is the very best working medium that can be 

 used for pen or brush work. Any ordinary saucer will do, and for 

 an inkstand buy a common brass thimble to which fit a cork. Fill 

 the thimble with water as a measure of the quantity of ink required. 

 Pour this into your saucer and rub up your India ink until you 

 think it sufficiently black. Then keep up the rubbing five or ten 

 minutes longer. Now add one drop only of glycerine, and rub a 

 little more, and the ink is made. To mount the inkstand, cut a 

 potato or turnip in half, scoop out a hollow for the thimble, using 

 the flat cut surface as a base for the inkstand, and when the pen 

 fouls, jab it into the vegetable, which will clean it. To pour the ink 

 from the saucer to the inkstand, make a long gutter of writing paper, 

 by which it can be poured in without spilling a drop. Lithographic 



