Ch. X] 



ISOLATION OF TISSUE ELEMENTS 



333 



put on and scaled (§ 508). If one adds congo-glycerin to a consid- 

 erable amount of the isolated material it may be kept and used 

 at any time. 



§ 519. Isolation of muscular fibers. - For this the formal disso- 

 ciator may be used (§516), but the nitric acid method is more suc- 

 cessful (§ 560). The fresh muscle is placed in this in a glass vessel. 

 At the ordinary temperature of a sitting room (20 degrees centigrade) 



Fig. 199. Moist Chamber and Moist Preparations. 



A Bowl (B) inverted over a plate (P) containing water and a glass shelf 

 supported on glass rods. The slides (S) are supported on the glass shelf. This 

 makes a very efficient and cheap moist chamber. 



B Cover-glasses (C) made slightly eccentric and containing between them 

 the object to be kept moist. By using cover-glasses the specimen can be examined 

 from both sides, and as part usually remains with each cover-glass, two perma- 

 nent preparations can be made. 



C Slide (S) with a cover-glass (C) extending slightly over one edge so that it 

 can be lifted up without danger of sliding it along and thus disarranging the 

 specimen. 



the connective tissue will be so far gelatinized in from one to three 

 days that it is easy to separate the fascicles and fibers either with 

 needles or by shaking in a test tube or shell vial with water. It 

 takes longer for some muscles to dissociate than others, even at the 

 same temperature, so one must try occasionally to see if the action 

 is sufficient. When it is, the acid is poured off and the muscles washed 

 gently with water to remove the acid. If one is ready to make the 

 preparations at once they may be isolated and mounted in water. 

 If it is desired to keep the specimen indefinitely or several days, the 

 water should be poured off and 2 % formaldehyde added. The sped- 



