4. Heller's Blood Test

A small quantity of the gastric filtrate in a test tube is mixed with the same quantity of normal urine, and sodium-hydrate solution is added until a decided alkaline reaction is obtained. The tube is now heated over the spirit lamp until it begins to boil. The appearance of a flaky dark-red sediment proves blood (the reaction consists in the formation of haematin and its combination with the precipitated phosphates).

5. Schonbein-Almen's Blood Test

An emulsion of equal parts of freshly prepared guaiac tincture and ozonized oil of turpentine (i.e., old oil of turpentine that has been exposed to the air) is poured into a test tube over the gastric filtrate: a white ring forms at the point where both mixtures meet, which ring assumes a Prussian blue color if haemoglobin is present. Instead of ozonized oil of turpentine the following solution, which was proposed by Huhnerfeld. may be used:

1H. Weber: Berliner klin. Wochenschr., 1893. No. 19. 2J. Boas: "Diagnostik und Therapie der Magenkrankheiten," Theil 1, 3te Auflage, p. 206.

℞ Acid, acetic, glacial., .................................................2

Aq. dest, • • ••• • • • 1

Terebinthin. et spirit Tin. rectif.....aa 100

6. Teichmanns Hoemin Test

A small quantity of the gastric contents is evaporated in a porcelain dish over a spirit lamp. A small part of the residue is placed on an object-glass and mixed with a quantity of pulverized common table salt. A drop of glacial acetic acid is poured over it, covered with a cover-glass, and slightly heated over a spirit lamp until small bubbles begin to rise. Another drop of acetic acid is now again added, and the specimen examined under the microscope. The presence of haemin crystals (rhomboid shape and beautiful reddish color) proves blood.

7. Korczynski And Jaworski's1 Blood Test

A small quantity of the filtered residue is placed in a small porcelain dish, a trace of chlorate of potassium and a drop of concentrated muriatic acid are added, and the mixture is slowly heated over a spirit lamp. After all the chlorine gas has escaped, one to two drops of a dilute solution of potassium ferrocyanide are added; a distinctly blue color (Berlin blue) arises if blood is present.

Pus

Pus is very seldom found in the gastric contents and is recognized by its characteristic appearance under the microscope.

1 Korczynski und Jaworski: Deutsche med. Wochenechr., 1887, Nos. 47-49, p. 85.