PRACTICAL PHOTO-MICROGRAPHY. 119 



to replace the quantity taken out by the prints, and each time 

 gold is added the bath should be tested for acidity and alkalized 

 slightly if necessary. The gold salt is usually sold in sealed 

 tubes containing fifteen grains ; one of tjiese tubes may be 

 scratched with a file, put into a two-ounce bottle, the tube broken 

 and water added to fill the bottle. One dram of this contains 

 about one grain of gold chloride, and a sheet of paper (17x22 

 inches) may be expected to take up about one grain of gold salt. 



From the fresh water after toning the prints are to be put 

 into a fixing bath of sodic hyposulphite, made decidedly alka- 

 line, as on page 64. In this they are to be kept separate, in 

 motion, and for a period ranging from 32 to 18 minutes. A 

 very light print may be removed in case of need after 8 or 10 

 minutes. The prints, if on " double albumenized " paper a 

 quality having a high gloss are to be put direct from the 

 hypo bath into water containing, to each pint, about an ounce 

 of common salt ; this is to prevent blisters, which are apt to 

 occur. Then the prints must be very thoroughly washed, an 

 easy matter if the proper means be taken, a very difficult one 

 if commercial washing machines are the only apparatus used. 

 Our plan is to lay each print down on a slab of glass or vul- 

 canite under a rose tap, and to pass a squeegee many times 

 briskly over the back of the print, occasionally turning the 

 print face upwards to get some water, but not any squeegeeing, 

 of course. 



After a few changes of water and applications such as this, one 

 of the washing machines may be trusted to finish the elimina- 

 tion of the hypo, in four to six hours ; the water running con- 

 stantly and being syphoned oft from the 'bottom of the washing 

 trough. After thorough washing, the prints may be dried or 

 blotted off, but before they are quite dry they should be rolled 

 one by one, face outwards, round a ruler or other roller of hard 

 wood, and there left till they are dry, or till they retain the 

 outward curl. 



The effect of glazing or enamelling the face of a print is to 

 produce an appearance not, perhaps, artistic, but in some cases, 

 such as ours, desirable. The shadow details are greatly assisted 

 by this gloss. The simplest way we know to impart a gloss to 

 the albumen print is to place the print, washed but still wet, 



