xi THE ALBUMINOIDS : ALBUMOIDS 577 



insoluble in water and in salt - solutions, but soluble in alkalies. 

 Whether this substance, coagulating at 60, is the albumin of the 

 sarcolemma or coagulated myosin is uncertain. 



Membranin is the term which Morner l has given to the substance 

 forming Descemet's membrane. He has isolated it and finds it gives 

 the following reactions : It is insoluble in water, in salt-solutions, and in 

 cold, dilute acids and alkalies ; it dissolves, however, in boiling water, 

 in acids and alkalies, and forms a gelatinising fluid. It gives a distinct 

 biuret- and lead-sulphide reaction, a feeble furfurol reaction, but very 

 intense Millon's and xanthoproteic reactions. By boiling with acids 

 a reducing substance is split off, which is not due to an admixture of 

 mucin. 



Osseo-albumoid is a substance which Hawk and Gies 2 prepared 

 from powdered bone after having removed all soluble albumin, mucoid, 

 and gelatine. 



Chondro-albumoid has been prepared in a similar manner from 

 cartilage. 3 



The lens-albumoid was described by Morner, 4 after Knies 5 had 

 shown that lenses suffering from cataract were not composed of keratin, 

 but of an albumin which was digested by pepsin. This albumoid is 

 .insoluble in water and in salt-solutions, with great difficulty soluble in 

 acetic acid and ammonia, but readily soluble in very dilute HC1 or KOH. 

 It is precipitated from its solutions on neutralisation and by ferrocyanic 

 acid. It is salted out by completely saturated solutions of sodium 

 chloride and sodium sulphate and by half -saturated solutions of 

 ammonium and magnesium sulphates. Its coagulation-temperature 

 Morner gives as very low, namely, between 43 and 47. The 

 albumoid gives the reactions of Millon, Adamkiewicz, and Liebermann, 

 and the lead-sulphide test. A carbohydrate seems to be absent. 



The albumoid in conjunction with two globulins, the a- and 

 /5-crystallin, builds up the lens fibres. In the lenses of fully-grown 

 cattle examined by Morner, the albumoid amounts to 48 per cent of 

 the albumins in the lens and to 1 7 per cent of the fresh lens ; its amount 

 varies, however, with age, as it is much more abundant in the inner 

 [older portions than in the outer younger ones. 



The Ohm-da Dorsalis Albumoid. Stenberg 6 has shown that the 



1 G. T. Morner, Zeitschrift fur physiol. Chemie, 18. 233 (1893). 



2 P. B. Hawk and W. J. Gies, American Journ. of Physiol. 7. 340 (1902). 



3 P. B. Hawk and W. J. Gies, American Journ. of PhysioL 7- 340 (1902) ; C. T. 

 Morner, Skandinav. Arch.f. PhysioL 1. 210 (1889). 



4 C. T. Morner, Zeitschr. f. physiol. Ghem. 18. 61 (1893). 



5 M. Knies, Untersuchungen aus dem Physiol. Institut Heiddberg, 1. 114 (1877). 



6 S. Stenberg, Arch.f. Anat. u. PhysioL Anat. Abteil. 1881, p. 105. 



2 P 



