116 THE AMERICAN MONTHLY [April 



For a dark room light, an artificial one is best as it is 

 always of equal intensity and is available at all times, 

 night or day. The Carbutt "Miiltum in Parvo" lantern is 

 excellent, as it furnishes abundant light and has two side 

 doors, one opening directly to the lamp by Avhich contact 

 lantern slide exposures ma}^ be made, and another haviug 

 an opal glass Av^hich is excellent for examining the fixed 

 negatives. 



For a fixing solution, a plain solution of sodium hypo- 

 sulphite in water answers well, but one having chrome 

 alum as an ingredient is better. Carbutt's formula is a 

 most excellent one. It appears to have a slight clearing- 

 action, due probably to its removing staining if present ; 

 and as it hardens the film, the negative is easier to 

 handle, particularly during warm weather. Its compos- 

 ition is as follows : 



Sulphuric Acid 2 c. c. 



Sodium Hyijosulphite 2l0giaiumes 



Sodium Sulphite :>0 ' 



Chrome Alum 15 " 



Water 1000 c. c 



This fixing bath keeps well and may he used repeatedly. 

 After thorough fixing, washing, and drying, tlie pro- 

 cess is completed so far as the negative is concerned, ex- 

 cept in a few special cases where reduction or intensifi- 

 cation is required. These processes should be avoided 

 whenever possible and should only be necessary in the 

 case of objects especially difficult to photograph. It is 

 frequently the case that a first exposure does not give an 

 entirely satisfactory negative. When this occurs, instead 

 of attempting to better the poor negative by reduction or 

 intensification, another exposure should be made of 

 shorter or longer duration as indicated by the first nega- 

 tive, and a better or perfect result can thus usually be 

 obtained. With some difficult subjects, however, no at- 

 tention to exposure or subsequent careful development 



