162 W» Crookes on the Wax-paper Photographic Process. 



Two gauze burners. 

 One box iron. 

 Filtering paper. 

 A still for water. 



One platinum, and three bone spatulas, (flat paper knives). 

 Six funnels. 

 One funnel stand. 



Pint, half pint, one ounce, and one drachm, measures. 

 Three glass flasks. 

 Boxes for holding paper. 

 Scales and weights. 



Sponge, glass rods, stoppered bottles, &c. 



8. The dishes may be made of glass, porcelain, or gutta percha. 

 Glass and porcelain are certainly cleaner than gutta percha ; but 

 for general use the latter is far preferable, as with it there is no 

 risk of breakage, and the bottom of the dish can be made per- 

 fectly flat, which is a great advantage. These dishes should be 

 made of sufficient length to allow of a margin of about half an 

 inch at each end when the paper is in ; and the shape should be 

 made as nearly square as possible, by arranging them to take 

 two or three sheets side by side. 



The gutta percha should be of a good thickness, otherwise it 

 will bend and give way, if it be moved when full of liquid. 

 The depth must depend upon the size of the dish, and the pur- 

 pose for which it is intended. The dishes in use here accomodate 

 three sheets of paper side by side ; they are fifteen inches square^ 

 and one inch and a half deep. I think, however, for some 

 purposes, where they are not wanted to be moved about much, 

 (i. e. those for holding the bath of hyposulphite of soda for 

 fixing,) the depth might be advantageously increased to two 

 inches and a half. Each dish ought to be reserved for a particu- 

 lar solution, and should have a piece of mill board a little longer 

 than itself for a cover. 



9. The brushes for cleaning the dishes are of two sorts ; a 

 common scrubbing brush will be found the best for all parts but 

 the corners, and for these another kind must be used, having a 

 handle about a foot long, at the end of which are tufts of stiff 

 bristles, projecting about three quarters of an inch, and radiating 

 on all sides, forming a ball about two inches and a half in diam- 

 eter. Hardly any dirt will be found capable of resisting this 

 brush, if it be pressed into a corner, and twisted round several 

 times. The dishes ought always to be put away clean, as the 

 dirt is much more difficultly removed if allowed to dry on. 



10. When a dish is to be cleaned, if it be of glass or porcelain, 

 strong nitric acid must be poured into it; if of gutta percha, it 

 should be filled with a strong solution of cyanid of potassium. 

 After soaking for half an hour or an hour, according to the state 



