PRACTICAL PHOTO-MICKOGEAPHY. 63 



FIXING SOLUTION. 



Sodic hyposulphite 1 part 



Water 4 parts to 5 parts 



Made decidedly alkaline with a carbonate or with liq. amm. 



CLEARING SOLUTION. 



Concentrated solution of potash alum 1 pint 



Citric acid 3 ounces 



Hydrochloric acid , 2 drams 



If used before fixing the acids should be omitted. 



REDUCING SOLUTION. No. 1. (Farmer.) 



A. Potassic ferricyanide (red prussiate of potash) 10 grains 



Water 1 ounce 



B. The ordinary " hypo " solution. 



REDUCING SOLUTION. No. 2. 



A. Perchloride of iron. (Druggist's tincture or satu- 



rated aqueous sol.) 2 drams 



Hydrochloric acid 4 drams 



Water to 20 ounces 



B. Fresh hypo, solution 



(This is probably superior to the Ferricyanide Reducer for 

 lantern slides.) 



INTENSIFYING SOLUTIONS. 



a. Mercuric bichloride 1 part 



Water 20 parts 



Hydrochloric acid 5 part 



b. Sodic sulphite 1 part 



Water 8 to 10 parts 



THE FERROUS OXALATE DEVELOPER. 



A. Saturated solution at 60 deg. Fahr. of potassic oxalate, 



B. 1 to 3 aqueous solution of Ferrous sulphate, to each pint of which 



latter is added sulphuric acid, 1 dram. (Water 3 parts ; Iron 1 

 part, by weight). 



Notes : A " saturated " solution of potassic oxalate will hold 

 about 1 part by weight of the salt to 4 parts by weight of 

 water. 



The water may in each case be boiled to facilitate solu- 

 tion. The sulphuric acid is to be put into the water before 

 the iron salt is added. 



