128 THE A B C OF PHOTO - MICROGRAPHY 



of the bottle. It will be good for use so long 

 as any precipitate remains. 



The negative to be intensified (which must 

 be absolutely free from hypo), after being 

 well wetted, is immersed in A until bleached 

 to the desired extent. If great density is 

 required it should be whitened entirely 

 through the back, but merely grayed over 

 the surface if but slight intensification is 

 desired. It must then be very freely washed 

 for fifteen minutes in running water, or sev- 

 eral changes if the former is not convenient. 

 And herein lies one of the cardinal factors in 

 the permanence of the negative thorough 

 washing at every stage of its making. In the 

 quaint diction of the formula as found in 

 the old Journal 



" Three rules, which must be carefully obeyed, are 

 necessary to insure permanence in the intensified nega- 

 tive. And what is the first rule? Wash thoroughly. 

 And what is the second rule ? Wash thoroughly. And 

 what again is the third? Wash thoroughly. " 



The negative is now to be immersed in Solu- 

 tion B until completely blackened through on 

 the back; then again "washed thoroughly" and 

 placed in a rack to dry spontaneously. Thus 

 treated it will never change in any manner 

 more than one which has not been intensified. 



