117 



Use as egg albumen. Float sections on water slightly yellow with 

 potassium dichromate. Stretch over warm plate. Melting the paraffin 

 does not impair the efficiency of the fixative. When aqueous stains are 

 used, no previous treatment is necessary; but when alcoholic stains only 

 are to be used, it is best to set the slides for a short time in water to 

 dissolve the excess of fixative adhering to the slide. Otherwise this 

 precipitate will take the stain and spoil the appearance of the slide. 



Method of holding microscopic slidt-s in biass sprinas ior staininj: 



This is best done before the paraffin is removed from the slides. The 

 slides should be re-dried. 



A hot-plate for stretching paraffin ribbons that is a great improve- 

 ment over the old copper plate and gas flame may be made by putting 

 an incandescent lamp in a box and making a glass lid. The heat is 

 uniform. The glass plate gives better contact, though it is better to fill 

 the space between the slide and the glass lid by putting a drop of water 

 on the lid before placing the slide on it. A small box may be made of 

 an ordinary chalk box, the sliding lid of which is replaced by a dis- 

 carded photographic plate or other piece of glass. It is easier to remove 

 the slides, however, if the lid is flush with the sides of the box. 



