164 W. Crookes on the Wax paper Photographic Process. 



to "heat the water over a charcoal or coke fire, in preference to 

 using gas for this purpose. 



16. A platinum spatula is a most necessary instrument in 

 almost every operation ; the best size is 4 inches long, -J an inch 

 wide at one end, and f at the other, the corners being rounded 

 off, it should be of a sufficient substance to prevent its being 

 easily bent. Its chief use is, to raise one corner of the sheets to 

 allow of their being held between the finger and thumb, for the 

 purpose of removing from one dish to another, as, previous to 

 fixing, none of the solutions should come in contact with the 

 fingers. 



During the fixing and subsequent washing, bone spatulas will 

 be found very useful ; but after having been in contact with hy- 

 posulphite of soda, they must be carefully kept away from any 

 of the previous baths, or black stains will infallibly ensue. 



17. The funnels maybe either of glass or porcelain ; it will 

 be found useful to have several of different sizes, from two inches 

 diameter, up to six inches. A convenient stand for them may 

 be made of a piece of flat board, with circular holes, about half 

 the diameter of the funnels employed, drilled into it, and sup- 

 ported upon four legs about eight inches high. The paper used 

 for filtering should be the finest of the two sorts of blotting 

 paper mentioned above (14). The filters can either be cut from 

 the sheet as wanted, or they may be obtained ready cut in 

 packets. 



The measures should be of glass, graduated, the pint and half 

 pint into ounces, the ounce measure into drachms, and the 

 drachm measure into minims ; they should be rather long in 

 proportion to their width. 



The Florence oil flasks, which can be obtained for a trifle at 

 any warehouse, will be found to answer every purpose, nearly as 

 well as the more expensive German flasks. They must be 

 cleansed thoroughly from the adhering oil ; this may be done by 

 boiling in them, over the gauze gas burner, a strong solution of 

 ordinary washing soda, and afterwards well rinsing out with 

 water. 



18. It will be found indispensable, where there are many 

 operations going on at the same time, and many different sheets 

 of paper in various stages of progress, to have a separate box or 

 division to hold the paper in each of its stages. The plan I have 

 found most convenient, is to obtain several mill-board boxes, the 

 fronts of which will fall flat when the lid is lifted up, similar to 

 those used by stationers for holding letter paper, &c. : they can 

 be made to hold two or three piles of sheets side by side. 



The scales and weights need not be of any great accuracy. A 

 six inch beam capable of turning to half a grain, when loaded 

 with 500 grains in each pan, will be all that is requisite ; the 



