MUSCULAR TISSUE 



369 



hydrogen sulphide (do not use an excess of hydrogen sulphide) then warm 

 the mixture for a few moments and filter while hot. Concentrate the filtrate 



FIG. 117. HYPOXANTHINE SILVER NITRATE. 

 (Drawn from a student preparation by Dr. E. F. Hirsch.) 



to a small volume and put away in a cool place for crystallization (Fig. 116, 

 page 362). To obtain xanthine in crystalline form special precautions are 



FIG. 1 1 8. XANTHINE SILVER NITRATE. 



generally necessary. Evaporate the solution to dryness and test according to 

 directions given in Chapter VI on Nucleic Acids. 



