396 



Dr. C. A. MacMunn. 



TJrohcematin and Hcematoporphyrin. — Since I described urohaematin 

 I have met with it five times, four times in the nrine of acute rheu- 

 matism and once in the urine of a case of so-called "idiopathic" 

 pericarditis. Its occurrence in the urine in the former disease appears 

 to be pretty constant, and this is interesting when its artificial produc- 

 tion is borne in mind, since it is produced by the action of nascent 

 hydrogen on acid hsematin. It would seem to indicate that an acid 

 fermentation, attended by the destruction of considerable quantities of 

 haemoglobin, is present in that disease, and this agrees with the well- 

 known fact that a product of such fermentation is present in the 

 blood of acute rheumatism, namely, lactic acid.* Since this acid is 

 produced from glycogen (as well as in the muscles), and since haemo- 

 globin is broken down in the spleen and sent into the liver (being 

 helped there by the rhythmical contraction of the spleen, which Roy 

 has discovered), to be changed into the colouring-matters of bile and 

 urine, it would appear that the liver is the principal seat of this pecu- 

 liar fermentation. The presence of urohaematin in the urine at all 

 events indicates that the normal oxidation of haemoglobin down into 

 urobilin is not taking place, and that probably the bodies with which 

 urohaematin is associated are also insufficiently oxidised. Hence its 

 occurrence is of great pathological importance. I find that when 

 present in sufficient quantity it can be detected without isolation, as its 

 bands are easily seen in the urine itself. In this liquid it can be made 

 to show two spectra which are equally characteristic, namely, that of 

 acid and neutral urohoematin, and these can be distinguished from those 

 of methaemoglobin or of haematin, by the use of sulphide of ammo- 

 nium, as this has no effect on urohaematin. 



It occurs in the urine in the condition of neutral or slightly alkaline 

 urohaematin, and this shows four bands — a feeble one between C and 

 D, two between D and E, and a third close to F (see sp. 16) ; 

 the second and third bands might easily be mistaken for acid 

 methaemoglobin, but sulphide of ammonium, as stated above, serves to 

 distinguish them. Moreover, when it is present, Day's test fai]s to 

 give a blue coloration. The bands just referred to gave in the urine 

 the following measurements : — 



1st Band X620— 608 



2nd „ \580— 561 



3rd „ X542— 530 



4th „ X507— 486 



* The presence of lactic acid in the blood of patients suffering from acute rheu- 

 matism is inferred from the experiments of Dr. Richardson. There is at all events 

 an excessive production of acid of some kind in that disease. I failed to produce 

 any endo- or peri-carditis in guinea-pigs and rabbits by the injection of lactic acid 

 into their peritoneal cavities. 



