150 PRACTICAL HISTOLOGY. 



albumin, are employed. These may be preserved for a 

 considerable time by placing them, together with a piece of 

 camphor, in glass vessels, which have been thoroughly 

 cleansed by boiling water, to destroy bacterial germs or 

 other causes of putrefaction. 



267. Iodised serum is thus prepared : Add iCC tincture 

 of iodine and one or two drops of carbolic acid to looCC 

 fresh amniotic fluid, and filter. 



268. Dilute Albumin should only be had recourse to 

 when serous fluids cannot be obtained. It is thus pre- 

 pared : Dissolve 2 grammes dried sodium chloride in 

 25oCC water; add 28 grammes egg albumin, 2'$CC 

 tincture of iodine, two or three drops carbolic acid. Mix 

 thoroughly, and filter. 



269. Salt Solution is a | per cent solution of common 

 salt prepared thus : Heat sodium chloride to redness, cool 

 it over sulphuric acid, and dissolve 7-5 grammes in loooCC 

 distilled water. This fluid, though often termed indif- 

 ferent, is not in reality so. It is very convenient, but a 



serous fluid is always to be preferred when indifference is 

 really desired. 



270. Moist Chambers. Living tissues require to be 



kept moist. For this purpose 

 they are placed in a chamber, 

 the air of which is kept satu- 

 rated with moisture. 



Schultze's modification of Reck - 

 linghausen's moist chamber is a well- 

 known form of this apparatus (Fig. 

 52). It is a glass cylinder similar 

 to the lower part of an ordinary 

 lamp-chimney fixed to a plate of 

 glass. The object is laid under a 

 cover-glass ; the air of the chamber 

 is kept moist with strips of wet 

 blotting-paper. The tube of the 

 microscope fits into the cylinder, 

 FIG. 52. Recklinghausen and Schultze's and evaporation is prevented by a 



piece of soft leather interposed be- 

 tween the two. In the original chamber devised by Recklinghausen, 

 a piece of thin caoutchouc was tied round a simple glass cylinder 



