58 CARBON-MONOXID 'HEMOGLOBIN. 



served blood-corpuscles methemacytosis. Lesser degrees of the latter may recede 

 spontaneously in the body without destruction of the erythrocytes. Profound 

 influences resulting in the production of methemoglobin destroy the blood- 

 corpuscles and require transfusion. 



Preparation of Crystals. To the solution of isolated erythrocytes described on 

 p. 37 is added double its volume of a concentrated solution of ammonium sul- 

 phate, and evaporation is permitted to take place in the cold. There form brown- 

 ish-red needles, prisms or plates with marked pleochroism. Methemoglobin 

 develops in part spontaneously in the body, as, for instance, in bloody urine, 

 in the sanguinolent contents of cysts, in old extravasates and in dried blood- 

 crusts. The addition of a trace of ammonia to a solution of methemoglobin pro- 

 duces an alkaline solution of methemoglobin, which exhibits two bands similar to 

 those of oxyhemoglobin, but of which the first is the wider and extends the more 

 toward the red. If a reducing solution of ammonium sulphid be added to solu- 

 tions of methemoglobin, reduced hemoglobin develops. 



CARBON-MONOXID HEMOGLOBIN AND CARBON-MONOXID 



POISONING. 



Carbon-monoxid hemoglobin is a more stable combination than the 

 preceding and is produced when carbon monoxid is brought into con- 

 tact with hemoglobin or oxyhemoglobin. It is cherry-red in color, 

 not dichroic, and it exhibits in the spectrum two absorption-bands 

 that closely resemble those of oxyhemoglobin, but are somewhat 

 closer together and more toward the violet (Fig. 15, 3). It can be 

 readily recognized, however, from the fact that reducing substances, 

 which influence the oxyhemoglobin, do not dissolve these bands, that 

 is, do not transform the carbon-monoxid hemoglobin into reduced 

 hemoglobin. A further means of recognition consists in the sodium- 

 test: a 10 per cent, solution of sodium hydroxid added to carbon-mon- 

 oxid hemoglobin and heated gives rise to a cinnabar-red color. The 

 same solution added to oxyhemoglobin produces a black-brown- 

 greenish mass. The spectrum-analytical examination and the sodium- 

 test permit the recognition of three-tenths carbon-monoxid hemoglobin 

 mixed with seven-tenths oxyhemoglobin. 



Carbon-monoxid hemoglobin reactions : Modified sodium-test: The blood is 

 diluted 20 times and an equal amount of sodium hydroxid of a specific gravity 

 of 1.34 is added in a test tube. Carbon-monoxid blood assumes a beauti- 

 ful red color after addition of ammonium sulphid 2 grams of sulphur being 

 added to 100 grams of yellow ammonium sulphid and 30 per cent, acetic acid, 

 while normal blood assumed a greenish-gray coloration. Both kinds of blood 

 exhibit also differences in color when treated as follows: Dilute potassic 

 hydrate is added, and then a few drops of a watery solution of pyrogallic acid; 

 the mixture is shaken at once and permitted to stand protected from the air. 

 For the purpose of the test, blood made lake-colored with water may be used, 

 as well as blood in which the erythrocytes are preserved by addition of 

 concentrated solution of sodium sulphate. Three cu. cm. of blood are diluted 

 with 1 1 oo cu. cm. of water; 10 cu. cm. of this are mixed with 2 cu. cm. of 

 2 per cent, solution of grape-sugar and 2 cu. cm. of saturated solution of barium 

 carbonate or lime-water, and the whole is heated almost to the boiling-point. 

 From 4 to 5 volumes of lead acetate added to the blood cause a distinct differ- 

 ence accordingly as oxygen or carbon-monoxid blood is present. 



Oxidizing substances, as, for instance, solutions of potassium permanganate 

 0.025 per cent., potassium chlorate 5 per cent., and dilute chlorin-water, render 

 solutions of carbon-monoxid hemoglobin cherry-red, while they render solutions 

 of oxyhemoglobin pale yellow. Both varieties of hemoglobin thus treated acquire 

 the bands of methemoglobin, the carbon-monoxid hemoglobin considerably later. 

 Subsequent addition of ammonium sulphid transforms the forms of hemoglobin 

 thus altered back again into oxyhemoglobin and carbon-monoxid hemoglobin. 



By reason of its greater constancy carbon-monoxid hemoglobin resists putre- 

 faction for a long time, as well as the action o hydrogen sulphid. 



