CHAP. II.] HEMI-ALBUMOSE AND PROTO-ALBUMOSE. 125 



appears to the Author that we may with advantage retain the term 

 henii-albiimose for the mixed product containing all the albumoses. 



Method Blood fibrin affords a material from which the 



of obtaining m i xe d albumoses can be obtained with the greatest 

 hemi-albu- 



mose' (l.e. the ease ' 

 mixed albu- Fibrin obtained by stirring or whipping blood is 



moses) from thoroughly washed with water and it is then placed in 

 flbrin - 0'2 per cent. HC1 until it has swollen up into a jelly ; 



the acid and fibrin are heated to 37 and an active solution of pepsin 

 is then added, which causes solution of the fibrin to occur in the 

 course of very few minutes. Digestion may be allowed to go on for 

 about an hour and may then be stopped either by cooling the liquid 

 or, better still, by neutralising it with sodium hydrate. 



Kiihne and Chittenden in one of their experiments placed 1500 

 grammes of raw fibrin in 5 litres of HC1 (0*4 per cent.) for 24 hours, 

 then heated it to 45 C. and mixed with it 400 c.c. of normal artificial 

 gastric juice and digested the mixture for 1 hour 1 . 



An abundant precipitate falls which is separated by filtration, 

 and to the filtrate powdered sodium chloride is added in such 

 quantities that some remains undissolved and mixed with the abund- 

 ant white precipitate, which is collected in a filter and washed with 

 a little saturated NaCl solution. The product is hemi-albumose, i.e. 

 a mixture of the albumoses derived from the hemi-moiety of the 

 proteid molecule. 



Method of The product described in the preceding paragraph is 

 S ^ r u8 i ^ g ibu ( se P arate d fro m the filter and is pounded in a mortar 

 moses* from the together with a- saturated solution of NaCl, which 

 mixed 'hemi- dissolves and holds in solution the so-called deutero- 

 aibumose.' albumose, whilst proto-albumose, dys-albumose and 

 hetero-albumose remain undissolved. 



From the solution in NaCl above referred to deutero-albumose is 

 precipitated by means of acetic acid in which sodium chloride has 

 been dissolved. 



The separation of the albumoses thrown down by NaCl is effected 

 as follows. The mixed precipitate containing them is pressed so as 

 to free it as thoroughly as possible from adhering salt solution, and 

 is then treated with a considerable quantity of water, which dissolves 

 it almost entirely. The insoluble matter is separated by filtration 

 and ground in a mortar with 5 per cent, solution of NaCl, and then 

 with water, and constitutes the so-called dys-albumose. The united 

 solutions containing NaCl are dialysed, whereupon a precipitate occurs 

 of so-called hetero-albumose, whilst proto-albumose is left in solution. 



1 All the details, a knowledge of which is necessary for repeating Kiihne's experi- 

 ment, will be found in the paper by Chittenden and himself, 'Ueber Albumosen/ 

 Zi-itxchrift fiir Biologie, Vol. xx. (1884), pp. 1151: refer to p. 13. The reader may 

 also refer to a previous paper by the same authors, 'Ueber die nachsten Spaltungs- 

 produkte der Eiweiss-Korper ' Zeitschrift fiir Biologie, Vol. xix. (1883), pp. 159208 : 

 refer to pp. 184 and 185. 



