CARBON-MONOXIDE HAEMOGLOBIN. 287 



tion of carbon-monoxide haemoglobin, its absorption-spectrum is of the 

 greatest importance. This spectrum shows two bands which are very 

 similar to those of oxyha3moglobin, but they occur more toward the violet 

 part of the spectrum. The middle of the first band corresponds to 

 X = 570, and the second to X = 542 (LEWIN, MIETHE and STENGER). 

 These bands do not change noticeably on the addition of reducing 

 substances; this constitutes an important difference between carbon- 

 monoxide haemoglobin and oxyhaemoglobin. If the blood contains oxy- 

 haBmoglobin and carbon-monoxide haemoglobin at the same time, we 

 obtain on the addition of a reducing substance (ammoniacal ferro-tar- 

 trate solution) a mixed spectrum originating from the haemoglobin and 

 carbon-monoxide haemoglobin. Carbon-monoxide haemoglobin also gives 

 a band in the violet A = 416. 



A great many reactions have been suggested for the detection of 

 carbon-monoxide haemoglobin in medico-legal cases. A simple and at 

 the same time a good one is HOPPE-SEYLER'S alkali test. The blood is 

 treated with double its volume of caustic-soda solution of 1.3 sp. gr., 

 by which ordinary blood is converted into a dingy brownish mass, which 

 when spread out on porcelain is brown with a shade of green. Carbon- 

 monoxide blood gives under the same conditions a red mass, which if 

 spread out on porcelain shows a beautiful red color. Several modifica- 

 tions of this test have been proposed. Another very good reagent is tan- 

 nic acid, which gives with dilute normal blood a brownish-green precip- 

 itate and with carbon-monoxide blood a pale crimson-red precipitate. 1 



As according to BOHR there are several oxyhaemoglobins, so also accord- 

 ing to BOHR and BocK, 2 there are several carbon-monoxide hemoglobins, with 

 different amounts of carbon monoxide. As haemoglobin can unite with oxygen 

 and carbon dioxide simultaneously, as shown by BOHR and TROUP, so also can it 

 unite with carbon monoxide and carbon dioxide simultaneously and independently 

 of each other. 



Carbon-monoxide methaemoglobin has been prepared by WEIL and v. ANREP 

 by the action of potassium permanganate on carbon-monoxide hemoglobin, 

 but this is contradicted by BERTIN-SANS and MOITESSIER. S Sulphur methaemo- 

 globin is the name given by HOPPE-SEYLER to that coloring-matter which is 

 formed by the action of sulphureted hydrogen upon oxyhaemoglobin and which 

 is generally designated sulphcemoglobin. The solution has a greenish-red, dirty 

 color, and shows two absorption-bands between C and D. This coloring-matter 

 is claimed to be the greenish color seen on the surface of putrefying flesh. Accord- 

 ing to HARNACK the conditions are different when H 2 S is passed through an 

 oxygen-free solution of haemoglobin (or carbon-monoxide haemoglobin). The 



1 In regard to this test (as suggested by Kunkel) and others we refer to Kostin, 

 Pfliiger's Arch., 84, which contains a very excellent summary of the literature on the 

 subject. See also de Domenicis, Chem. Centralbl., 1908, 2, p. 66. 



2 Centralbl. f. Physiol., 8, and Maly's Jahresber., 25. 



3 v. Anrep, Arch. f. (Anat. u.) Physiol., 1880; Sans and Moitessier, Compt. Rend., 

 113. 



