W. Crookes on the ee Process. 165 
A sponge will be found Ao ‘for wiping up any of the solu- 
tions that may have cm spilt on the bench. Solid glass stirring 
rods of about the thickness of a quill, and six or eight inches 
long, and a small medeetan pestle and mortar, are of great 
service in many of the operations. 
Stoppered bottles should be employed for all the solutions ; 
and too much care cannot be taken to label each bottle accurately 
and distinctly. 
19. Besides the above apparatus, the following materials and 
chemicals are requisite. A rough estimate is also given of their 
relative consumption in three months 
Photographic a 270 sheets, ¢ or 112 square feet. 
‘our pounds of 
hree ounces of iodid of ener 
Phree ounces of bromid of potass 
: ‘our ounces of nitrate of silver. 
5 _ Two ounces of glacial acetic acid. 
~ eadfour ounces of gallic acid. 
~ One pint of alcohol. : 
Seven pounds of hyposulphite of soda. 
Half a pound of cyanid of potassium. 
- Half a pint of concentrated nitric acid. 
__ Eighteen gallons of distilled water. 
20. The selection of a good sample of paper for the basis on 
a 
ance, as any imperfection will be a source of annoyance in every 
i fineked of the process, and will hardly fail to show itself on the 
‘fini ture. The paper, which from numerous ex ee 
to be superior to any other, is that 
in photographic is his is mannlietared with 
saan 
will be found by far the sa advantageous p ae when used 
as ls like the present, to order wholesale sta- 
ti nt cut 
ta: the requisite dimensions. The size of the sheets 
by aot inches*. Hitherto Messrs. 
Street, have supplied us with the 
21. I am indebted ey Mr. Barchiy of Regent Street, wax 
bleacher, for much valuable information concerning wax and its 
adulteratio tions, and for an extensive assortment of waxes of all 
_ * This i ® most inconvenient size, as it involves the cutting of more than one 
thind of the ps erto waste. The admirably ingenious arrangement of Mr. Ronald’s, 
was not ae the view of em) man rah copra paper; or it would doubtless 
have been contrived to accomodate of a size which could be cut with less 
2 ast much A544 by. 14 incben, ox 44 by 11 1ti 
