PHOTOGRAPHIC PROCESSES. 81 



Nos. I. and III. are placed in hot water till their 

 temperature reaches 120° Fahr. No. I. is now gra- 

 dually added to no. Ill with constant stirring and 

 shaking, no. Ill being placed in a bottle for the 

 purpose ; this process should take at least half an 

 hour. 



No. IV. Iodide of Potassium, 4 grs. 

 Distilled Water, 2 drachms. 



is now added, well shaken, and the whole boiled 

 for three quarters to one hour or more, according to 

 the sensitiveness required. No. II. from which all 

 the water has been removed being gradually added 

 with constant stirring during the boiling. 



The emulsion while hot is poured into a bowl to 

 set, and when cold placed in three thicknesses of 

 coarse muslin, through the pores of which it is 

 wrung out into a deep earthenware vessel. It is 

 washed with six changes of water with frequent 

 stirring for one hour. The ringing and washing 

 being repeated, the emulsion is thrown upon a hair 

 sieve to drain, a process that will take at least an 

 hour. 



We again dissolve it by heat, and after filtration 

 through cambric, neutralize it by the addition of a 

 few drops of a dilute solution of ammonia, (if great 

 sensitiveness is required). 



Two drachms of alcohol are finally added and the 

 whole put away for a couple of days. 



The most difficult parts of the pi'ocess are now 

 before us, and the amateur will find his skill, in- 



G 



