394 Source of Free Hydrochloric Acid in the Gastric Juice. [Apr. 15, 



sulphate. So he found that acetate of peroxide of iron was resolved by 

 dialysis into hydrated peroxide of iron and free acetic acid. It is possible 

 and probable that the albuminoid bodies present take part in determining 

 the contrast between colloid and crystalloid bodies. Graham found that by 

 dialysis he could separate free hydrochloric acid from the gastric juice thrown 

 up in vomiting. 



It may be further objected that anatomists are not agreed as to the struc- 

 ture of the corpuscles. But it will be seen that there is no more required 

 than may be regarded as established. The corpuscles act in many parti- 

 culars, if not in all, as if they were membranous sacs more or less distended 

 with fluid. They may be swollen by immersion in a thinner (less colloid) 

 fluid, and reduced by immersion in a more colloid fluid — that is, they are 

 susceptible of endosmosis and exosmosis as membranous sacs would be. In 

 their ordinary condition as seen under a microscope, they present the ap- 

 pearance of collapsed spherical or oval sacs or cells. They appear as double 

 concave disks. In swelling (by endosmosis) the lowest part of each con- 

 cavity is the last to take on the spherical contour, just as it would do if the 

 corpuscles were membranous sacs. The corpuscles sometimes so collapse 

 (by exosmosis) that one-half of the hollow sphere is reversed, while the 

 other half retains its form unchanged, the former sitting like a cup in the 

 latter — a conformation inconceivable on the theory of homogeneity of the 

 corpuscles as a whole. Crystallizable substances may be extracted from 

 the corpuscles by pressure and by endosmosis. They must have been in 

 solution in order to crystallization, and solution involves a fluid. The 

 liquid expressed from the corpuscles has an acid reaction, and contains an 

 organic acid and acid phosphates. It contains, among other bodies, the 

 haematoidin of Virchow. The ash of these crystals consists almost wholly 

 of metaphosphates*, which point directly to tribasic phosphoric acid in 

 solution, combined with one atom of fixed base, which is inconceiv- 

 able unless separated by membrane from the plasma, which is always 

 alkaline. 



In fine, whatever other peculiarities the blood-corpuscles may possess, 

 they have the requisites for furnishing acid phosphates in solution under 

 pressure, such as must attend engorgement of the capillaries in the walls of 

 the stomach. 



Let us glance at what takes place in all probability as the acid fluid 

 enters the gastric tubules. They are surrounded by a mixture of hydro- 

 chloric acid, acid salts, neutral salts, and albuminoid bodies. Dialysis 

 must be repeated, and a stronger acid solution pass into the sacs or cells 

 contained in them. The sacs swelling by endosmosis, and corroded by the 

 acid, must at length burst, and the liquid contents, together with the disin- 

 tegrated and partially digested membrane of the sacs, pass out into the 



* The ether-extract of the blood-corpuscles yields, according to Schwann, an ash con- 

 taining acid phosphate of soda. Owen, Sees, and Berzelius maintained the existence 

 of oleo-phosphoric acid in the corpuscles. 



