1906.] PLA.CEXTA IK UNGULATES. 89 



alcohol and ammonia) 50 mm. deep was examined in a long 

 spectroscope bottle, but no bands except the following could be 

 seen : — 



(1) A 594-5 - 572-5, 



(2) \ 556-5- 531. 



" Other experiments were made to prove that the pigment was 

 not hsematin ; e. g. ammonium sulphide was added, but no reduced 

 hsematin spectrum appeared. Caustic alkalis also failed to change 

 the spectrum into that of alkaline haematin, acids into that of acid 

 hfematin, which would have occurred if that pigment had been 

 present. 



" Let us now compare the spectrum of the pigment in alcoholic 

 solution with that of an as equally as possible dilute aqueous solu- 

 tion of oxyhaemoglobin : — 



Placenta pigment. Oxyhfemoglobin. 



(1) \ 593 - 574, (1) \ 586 - 568, 



(2) \ 556-5 - 531, (2) \ 552 - 525. 

 " (See Hoppe-Seyler, Handbuch, 1903.) 



" This pigment therefore appears to be more nearly related to 

 hsematoporphyrin than to any other known decomposition-product 

 of haemoglobin," 



IV. Solution obtained from the foetal cotyledons of the Cow by 

 the second method. 



" The alcoholic solution shows the two-banded spectrum, is the 

 colour of fairly deep sherry ; filtered, the filtrate is reddish yellow 

 and shows two bands : — 



(1) \ 593 - 577, second reading \ 594-5 — 575, 



(2) X 556-5 - 534-5, second reading \ 556-5 - 533-5, 



and in addition a faint shading nearer the violet. 



" The solution was evaporated on the water-bath, but owing to 

 the presence of some fatty matter remained fluid while hot. 



" An aqueous solution of the residue is faintly yellow, but shows 

 no bands or fluorescence. 



" The residue was brownish, in thin parts brownish yellow. The 

 absolute alcohol solution of this residue is reddish yellow with a 

 suspicion of greenish flviorescence ; it gives two faint bands : — 



(1) X 593 - 574, 



(2) X 558 - 536. 



" The violet end of the spectrum is cut ofi" at \ 487. 



" Ammonia produces turbidity, and diminishes, in the filtrate, 

 the intensity of the bands, but their position is unaltered. 



" On adding a little H^SO^ to an alcoholic solution slight 

 precipitation is produced. The filtrate is of a deep yellow sherry- 

 colour and the bands referred to above (in the Sheep) resembling 



