32 PRACTICAL PHYSIOLOGY. [iV. 



(ii.) Witli the filtrate A. test for phosjihoric acid by uranium acetate = 

 yellowish -white precipitate of -uranium phosphate (Ui'02)HP04. 



(iii.) Calciiun, by adding ammonium oxalate Ca.2C.2O4 + H.^O. Filter, and 

 when the filtrate is clear and gives no longer a precipitate with ammonium 

 oxalate, make it alkaline with NH4HO = after a time crystalline precipitate of 

 ammonio - magnesium phosphate MgNH4P04 + 6H2O, showing presence of 

 magnesium. 



3. examinatio:n" of a solution for proteids 

 and carbohydrates. 



I. Physical Characters. 



(a.) Note colour and transparency. Glycogen solution is 

 opalescent, starch and some proteid solutions less so. 



(h.) Taste. Salt solution may contain globulin. A sweet taste 

 indicates a sugar. 



(c.) Smell. The beef- tea odour of albumose and peptone solution, 

 and the smell of British gum are characteristic. 



(d.) Other characters. Thus a persistent froth is suggestive of 

 an albuminous solution. 



II. Test for proteids by xanthoproteic and Millon's tests. If 

 present : 



1. Test reaction to litmus paper. If acid or alkaline, test for 

 acid- or alkaH-albumin, and if either is present, neutralise, and 

 filter off precipitate. Test filtrate for proteoses and peptones as in 

 4 and 5. 



2. If original solution is neutral, acidulate faintly, and boil. A 

 coagulum may consist of native albumin, or globulin, or both. Filter; 

 and test filtrate for proteoses and peptones as in 4 and 5. 



3. Distinguish between albumin and globulin by (a.) dropping 

 solution into water, precipitate indicates globulin, {b.) saturating 

 solution with INIgSO^, precipitate = globulin, but may also contain 

 proto- and hetero-albumose. If precipitate obtained by (b), filter 

 and boil filtrate, coagulum = native-albumin. Distinguish between 

 egg- and serum-albumin by eth.er test. 



4. Add excess of NaHO, then, drop by drop, very dilute CuSO^, 

 pink colour indicates proteoses, or peptones, or both. 



5. Separate proteoses from peptones by saturating solution with 

 AmgSO^. Precipitate = proteoses. Filter ; and to filtrate add large 



