GLUTIN. 395 



extract the bone-earth, allow the remaining cartilage to lie for some 

 time in pure water in order to remove any adhering hydrochloric 

 acid, and finally boil it with water. Glutin obtained from bones, 

 skins, and tendons, has always a slightly yellow colour. 



Pure, colourless glutin can only be obtained from cellular 

 tissue, shavings of hartshorn, calves' feet, and the swimming- 

 bladder of certain fishes, by boiling them till they are thoroughly 

 dissolved, filtering them while hot, and removing from them all 

 foreign substances by the method recommended by Berzelius, 

 which has been already described. 



Combinations. On passing chlorine gas into an aqueous solu- 

 tion of glutin, each bubble of gas becomes enveloped in a glutinous 

 capsule ; the fluid itself becomes milky ; white flakes are observed 

 on its surface, and at the bottom of the vessel we observe a deposit 

 of a semi-transparent jelly. The substance which separates at the 

 surface has a frothy, snow-white appearance, is tough and elastic, 

 has a decided odour of chlorous acid, and can be dried at a tempe- 

 rature below 40 without becoming coloured ; after it has been 

 partially dried, it may be deprived of all its water at 100, and then 

 no longer evolves any odour of chlorous acid. In this state the 

 body is white, easily pulverisable, and insoluble both in water and 

 in alcohol. When ammonia is poured over it, nitrogen is deve- 

 loped, and hydrochlorate of ammonia and unchanged glutin are 

 left. 



Mulder* found that the action of chlorine and water on the 

 organic substance gives rise to the formation of hydrochloric and 

 chlorous acids, the latter of which enters into combination with 

 the unchanged glutin, the compound consisting of 1 equivalent of 

 acid and 4 equivalents of glutin. 



Assuming that the composition of this substance is represented 

 by the formula C 52 H 40 N 8 O 20 + C1O 3 , its atomic weight^ 8544-26. 

 Mulder has found two other combinations of glutin with chlorous 

 acid in the above mentioned gelatinous deposit of the solution of 

 glutin ; one consisting of 1 atom of glutin with 1 atom of chlorous 

 acid=C 13 H 10 N 2 O 5 + ClO 3 , and the other of 3 atoms of glutin and 

 2 atoms of acid=C 39 H 30 N 6 O 15 + 2C!O 3 . 



The action of acids on glutin has on the whole been as yet 



little examined ; with dilute mineral acids it appears to enter into 



combinations, which, however, on cooling, gelatinise in the same 



manner as pure glutin. Concentrated acetic acid dissolves glutin 



* Bull. de. Nferl. T. 2, p. 162. 



