EXAMINATION OF BLOOD. 53 



(a) Test of Katayama. Add 5 drops of blood containing 

 carbon monoxide to 10 cc. of water, then add 5 drops of 

 orange-colored ammonium sulphide and, after mixing, 10 

 drops of acetic acid or as much as may be necessary to make 

 the mixture faintly acid. With the blood containing carbon 

 monoxide a rose-red color appears, with the normal blood a 

 dirty greenish-gray color. The color is still perceptible with 

 one part of the carbon monoxide blood to five of normal blood. 



(6) Test of Kunkel. Mix carbon monoxide blood with 

 four times its volume of water. To a measured quantity of 

 this mixture add an equal volume of a 3 per cent, tannin 

 solution. Repeat with normal blood and note any difference, 

 especially on standing. 



(c) Rubner's Test. Add to the undiluted blood four to 

 five times the volume of basic lead acetate solution and shake 

 thoroughly for a minute. The carbon monoxide blood turns 

 a beautiful red, the normal blood a brown. After standing 

 for some time the normal blood gradually becomes a chocolate 

 and brownish gray, while the carbon monoxide blood remains 

 unchanged. 



The tests (6) and (c) are especially distinct when the mix- 

 tures are allowed to stand for some time in the test-tubes. 

 They show carbon monoxide blood in the presence of normal 

 blood, in the proportion of 1 to 6 or even 1 to 10. They are 

 therefore especially suited to detect small quantities of carbon 

 monoxide in blood. 



VIII. Alkaline Haematin Solution. 



By heating as well as by the action of alkalies or acids the 

 haemoglobin is split up into coagulated albumin and a pigment. 

 The pigment is different, according as haemoglobin is decom- 

 posed in the absence of oxygen or oxyhsemoglobin in the 

 presence of oxygen (air). In the first case reduced hsema- 

 tin (hsemochromogen of Hoppe-Seyler) is formed, in the 

 latter hsematin or this together with haemochromogen. This 



