ELEMENTARY PHOTO-MICROGRAPHY. 109 



from the glass, or blisters it in such a way as to 

 disfigure the print. 



Running water, where available, is more effec- 

 tive in dissolving out the hypo, from which the 

 negative should be freed, though it has no special 

 virtue, as change of water is the main point. 

 Besides, it is often not obtainable, and leads to 

 waste. 



Sometimes a plate may have to be developed 

 late at night, when it would be risky to leave it 

 soaking in water till next day, especially in warm 

 weather. The Hypax tablet or Hypono solution 

 in such a case will be found an excellent substitute 

 for prolonged washing. After the plate has been 

 well rinsed, it is put in a dish and covered with 

 water. Half a tablet of Hypax or other hypo 

 eliminator is put in one corner until all has been 

 dissolved ; the negative is then rinsed in clean 

 water, and the hypo will have been eliminated. 



With some eliminators extreme caution is 

 necessary, because they cause the film to frill at 

 the edges, or even to come off altogether if the 

 plates be left long in the liquid. 

 FIXING BATH. 



A good fixing bath is made of four ounces hypo 

 dissolved in a pint of water. Vertical fixing in a 

 trough capable of fixing six negatives at a time is 

 recommended. After many plates have been fixed 



