118 PRACTICAL PHOTO-MICROGRAPHY. 



about ten minutes they are moved into a fresh supply of water. 

 If the paper is " ready sensitized " this second water should 

 contain a small dose of sodic carbonate sufficient to neutralize 

 the acidity of such paper. If the paper is home-made, and if 

 it is not brick red on entering the second water, a pinch of 

 common salt (sodic chloride) must be added to the second 

 water. The prints must go into the toning-bath red, not violet 

 or purple. As a rule the print should pass through four 

 changes of water before being toned. 



The toning-bath preferred by us, the only one we think it 

 necessary here to give will be found on page 64. It is to be 

 poured into a white perfectly clean flat dish large enough to 

 hold two prints side by side, and deep enough to allow one 

 print to slip easily under another. The temperature of the 

 toning-bath should be about 65 deg. Fahr., not under 60 deg. 

 nor over 70 deg. The prints are put in face downwards and 

 Jcept moving. The Toning Solution must be alkaline ; an acid 

 toning solution is the commonest of all amateurs' printing 

 troubles. The prints ought in from ten to twenty minutes to 

 change from brick red to a handsome color, brown, purple, or 

 warm blue-black according to taste and time. (Prints always 

 turn a little more blue after drying.) Home sensitized paper 

 usually tones more quickly than ready sensitized. It is an ad- 

 vantage to get as much gold as possible deposited without turn- 

 ing the prints blue ; that amounts to our saying that it is better 

 to tone slowly than quickly. If the bath is too strong in gold 

 the prints turn blue very quickly, but the blue is only superficial 

 and comes away in the fixing bath leaving the print practically 

 untoned. A fairly good rule is to stop the toning when the 

 print has, seen by reflected light, a good color inclined to be 

 warmer than we desire our finished print , seen by transmitted 

 light just a suspicion of blueness in the half tones of the higher 

 lights. 



After toning, the prints are put into clean cold water and 

 there kept moving if possible. A trace, however slight, of 

 hypo in the toning solution ruins it, the greatest care is there- 

 fore to be exercised to keep these solutions apart. The toning 

 bath should seldom be filtered, but gold chloride must be added 



