FECES 237 



with constant stirring to boiling and kept at the boiling temperature for several 

 minutes. After cooling, one-half of the mixture is transferred to a glass- 

 stoppered bottle of 80 c.c. capacity, 5 c.c. of glacial acetic acid and 25 c.c. of 

 ether are added, and the mixture is thoroughly shaken and allowed to stand for 

 several minutes. In a test tube, 2 c.c. of the ether extract are treated with 

 0.5 c.c. (i :6o) of the Lyle-Curtman guaiac reagent 1 and finally one to five drops 

 of 30 per cent perhydrol are added slowly from a pipette. A decided green, light 

 or dark blue, or purple color indicates the presence of blood in quantity to be of 

 clinical significance. 



, (c) Ortho-tolidin Test (Ruttan and Hardisty) 2 To i c.c. of a 4 per cent 

 glacial acetic acid solution of o-tolidin 3 in a test-tube add i c.c. of the solution 

 under examination and i c.c. of 3 per cent hydrogen peroxide. In the presence 

 of blood a bluish color develops (sometimes rather slowly) and persists for 

 some time (several hours in some instances). 



This test is said to be as sensitive for the detection of occult blood in 

 feces and stomach contents as is the benzidine reaction. It is also 

 claimed to be more satisfactory for urine than any other blood test. 

 The acetic acid solution may be kept for one month with no reduction 

 in delicacy. 



(d) Phenolphthalein Test. 4 ' Make a thin fecal suspension using about 5 c.c. of 

 distilled water. Heat to boiling, 5 cool and add 2 c.c. of the suspension to i c.c. of 



1 The Lyle-Curtman Guaiac Reagent. Fifty gm. of the ground crude gum guaiac are 

 treated in a beaker with 20 gm. of KOH dissolved in 200 c.c. of water. After thorough 

 stirring, the mixture is filtered with the aid of suction through cotton spread out in a thin 

 layer in a Buchner funnel. The residue is washed with water until the combined filtrate 

 and washings approximate 1.5 liters. To the diluted KOH solution are added with con- 

 stant stirring 21 c.c. of glacial acetic acid which is run dropwise from a burette. The 

 precipitate is allowed to settle, the supernatant liquid poured off, and the residue washed 

 once with water by decantation. The precipitate is then transferred to a Buchner funnel 

 and dried by suction as much as possible. The precipitate is gently heated (small portions 

 at a time) in an evaporating dish when most of the water separates and is removed by 

 filter paper. After the removal of the water, and while the mass is still plastic, it is drawn 

 out into thin sheets. In this condition the material rapidly hardens and dries in the air. 

 The dried masses are then ground, treated with 300 c.c. of hot 95 per cent alcohol and the 

 mixture is thoroughly stirred to prevent the formation of a gummy mass. In a few min- 

 utes a dark brown material separates in a flocculent condition. This is filtered, off and the 

 alcohol removed from the solution by distillation. The residue in the flask is treated 

 with 20 gm. of KOH dissolved in water, diluted considerably, and precipitated as before 

 with about 20 c.c. of glacial acetic acid. The precipitate is filtered off and dried as de- 

 scribed above, after which it is ground and kept in a desiccator. The weight of the material 

 finally obtained represents a yield of about 60 per cent. The time required to make this 

 preparation is 4 hours, the distillation of the alcohol being the most time-consuming of all 

 the operations. 



A solution containing i gm. of this preparation in 60 c.c. of 95 per cent alcohol may be 

 prepared and kept in a glass-stoppered bottle of colorless glass. This reagent does not 

 deteriorate for several weeks. 



2 Ruttan and Hardisty: Canadian Medical Ass'n Journal, Nov., 1912, also Biochemical 

 Bull., 2, 225, 1913. 



3 NH 2 NH, 



CH 3 CH 3 



4 Boas: Deut. med. Woch., 37, 62, 1911. 



5 Boas suggests using an ether extract of the fecal suspension thus eliminating the 

 necessity of boiling. However, oxidizing enzymes are the main sources of error here and the 

 action is easily and effectively eliminated by boiling. (See White: Boston Medical and 

 Surgical Journal, 164, 876, 1911.) 



