THE BILE. 



179 



looking drops. At the bottom of the test-tube, after two or three 

 hours, there is usually collected a nearly homogeneous layer of 

 this deposit, while the remainder continues to adhere to the sides 

 of the glass in small, circular, transparent drops. The deposit is 

 semi-fluid in consistency, and sticky, like Canada balsam or half- 

 melted resin ; and it is on this account that the ingredients compos- 

 ing it have been called the " resinous matters" of the bile. They 

 have, however, no real chemical relation with true resinous bodies, 

 since they both contain nitrogen, and differ from resins also in 

 other important particulars. 



At the end of twelve to twenty-four hours, the glyko-cholate of 

 soda begins to crystallize. The crystals radiate from various points 

 in the resinous deposit, and shoot upward into the supernatant 

 fluid, in white, silky bundles. (Fig. 47.) If some of these crystals 

 be removed and examined by the microscope, they are found to be 

 of a very delicate acicular form, running to a finely pointed 

 extremity, and radiating, as already mentioned, from a central 

 point. (Fig. 48.) As the ether evaporates, the crystals absorb 

 moisture from the air, and melt up rapidly into clear resinous 

 drops ; so that it is difficult to keep them under the microscope 

 long enough for a correct 



drawing and measurement. Flg ' 49 * 



The crystallization in the 

 test-tube goes on after the 

 first day, and the crystals in- 

 crease in quantity for three 

 or four, or even five or six 

 days, until the whole of the 

 glyko cholate of soda present 

 has assumed the solid form. 

 The tauro-cholate, however, 

 is uncrystallizable, and re- 

 mains in an amorphous con- 

 dition. If a portion of the 

 deposit be now removed and 

 examined by the microscope, 

 it is seen that the crystals of 

 glyko-cholate of soda have 

 increased considerably in thickness (Fig. 49), so that their trans- 

 verse diameter may be readily estimated. The uncrystallizable 

 tauro-cholate appears under the form of circular drops, varying 



GLYKO-CHOLATE AND TACRO-CHOLATE OF 

 SODA, FROM OX-BILE, after six days' crystalliza- 

 tion ' The g 1 y k - cholate is crystallized ; the tauro- 

 cholate is in fluid drops. 



