HANDBOOK FOR BIO-CHEMICAL LABORATORY. 97 



STOKES'S Reagent (Reducing Oxylicemoglobin). To a solu- 

 tion of ferrous sulphate add some citric or tartaric acid and 

 enough ammonia to make it alkaline. 



STRASSBURG'S Test (Bile Acids). Treat the liquid with 

 cane-sugar and dip a strip of filter-paper in this liquid. Dry 

 this carefully over a gas or alcohol flame and place a drop of 

 sulphuric acid thereon. In the presence of bile acids a red 

 coloration is produced on the paper. The liquid must be free 

 from albumin for this test. 



STRUYE'S Test (Blood in Urine). Treat the urine with 

 ammonia or caustic potash, and then add tannin and acetic 

 acid until the mixture has an acid reaction. In the presence 

 of blood a dark precipitate is formed. Filter, dry, and obtain 

 the characteristic hsemin crystals from the dry residue by the 

 addition of ammonium chloride and glacial acetic acid. (See 

 Teiclimann.) 



SZABO'S Test (HCl in Contents of Stomach). Equal 

 volumes of # solutions of ammonium sulpho-cyanide and of 

 sodic-ferric tartrate are mixed. On adding liquid containing 

 HCl to this solution, which is pale yellow, a brownish-red 

 color is produced. 



TAXRET'S Test (Albumin). Dissolve 3.32 grms. potassium 

 iodide and 1.35 grms. mercuric chloride (4 mols. KI to 1 mol. 

 HgCl a ) in 20 c.c. acetic acid and dilute to 60 c.c. When 

 this reagent is added to an albumin solution, a white precipi- 

 tate is produced. 



TAURUS". See Lang. 



TEICHMAXN'S Test (Hcemin Crystals). Place a few parti- 

 cles of the dry residue on a microscope-slide, add a grain of 

 common salt, and cover with a cover-glass. Now add some 



