248 DIGESTION. [CHAP. xxv. 



describes two kinds of fluid, the first being the normal, or that 

 obtained under the best conditions, the second, the morbid, or that 

 obtained after inflammation has commenced in the wound and in 

 the pancreas. 



The normal pancreatic fluid is a colourless, limpid fluid, viscid 

 and gluey, flowing slowly by large pearly or syrupy drops, and 

 becoming frothy on agitation. It has no characteristic odour it 

 has a slightly saltish taste, resembling that of the serum of the 

 blood. Bernard has always found it alkaline in reaction never 

 either acid or neutral. It coagulates by heat as completely as 

 white of egg, becoming completely solid, and not leaving a drop of 

 fluid. The mineral acids, likewise, cause it to coagulate, as also 

 the metallic salts, alcohol, and pyroxylic spirit. It is not coagu- 

 lated by dilute acetic, lactic, or hydrochloric acids. Alkalies 

 cause no precipitate in it, but redissolve that thrown down by 

 heat, acids, or alcohol. 



This constituent of the pancreatic fluid, which is coagulable by 

 heat, etc., although apparently identical with albumen, is not so; 

 it differs from albumen in the following point. When the coagulum 

 obtained from the pancreatic fluid by alcohol is dried, it can be 

 re- dissolved completely and readily in water, and it gives to the 

 water the peculiar viscidity of the pancreatic juice, and likewise its 

 physiological properties ; whilst albumen, treated in the same way, 

 undergoes scarcely any appreciable solution in water. 



At a high temperature, the pancreatic juice rapidly changes, is 

 decomposed, and loses its property of coagulating by heat. At a 

 low temperature, it may be preserved for many days when its 

 viscidity increases and it becomes of the consistence of a weak 

 jelly. Bernard has examined the pancreatic juice in rabbits, 

 horses, and birds, and has found it in all to exhibit the same 

 essential character as in dogs. 



We have already stated that the pancreatic fluid, or a piece of 

 the pancreas itself, is capable of promoting the transformation of 

 starch into sugar, and therefore of promoting the digestion of 

 amylaceous matters. But that this power does not belong exclu- 

 sively to the pancreatic fluid is evident, from the fact that other 

 fluids or animal substances are capable of producing similar trans- 

 formations. Bernard has shown by direct experiment, that the pan- 

 creatic fluid possesses the peculiar property, which is not enjoyed 

 by any other animal fluid, of modifying in a special manner or di- 

 gesting all the neutral fatty matters which are met with in food. 

 Thus by mixing fresh pancreatic juice, possessing the normal 



