392 



Prof. E. N. Horsford on the Source of 



[Apr. 15, 



How could free hydrochloric acid be secreted from the bloody which is an 

 alkaline fluid ? 



The blood freshly drawn consists of a fluid (the plasma) in which there 

 are swimming myriads of exceedingly minute irregularly spheroidal bodies 

 (the corpuscles). The plasma consists of two bodies, one of which, the 

 fibrine, spontaneously separates from the other, the serum. The corpuscles 

 are little sacs of delicate animal membrane enclosing a fluid. This fluid 

 has an acid reaction, and its ash contains a monobasic alkaline phosphate. 

 The fibrine of the plasma contains, according to Yirchow, a glycerophos- 

 phate of lime, though the plasma, as a whole, has an alkaline reaction, and 

 contains in its ash a great measure (11 per cent.) of chloride of sodium. 



The moist corpuscles constitute about one-half of the blood. 



I assume that in healthy digestion, as a consequence of increased flow 

 of blood to the gastric mucous membrane and of the normal elasticity of 

 the walls of the capillaries, there exists in the membrane a condition which 

 is the equivalent of engorgement. Under the pressure which attends this 

 condition, the corpuscles in contact with the walls of the capillaries would 

 discharge a portion of their acid contents, which, with the adjacent plasma, 

 would pass through the walls of the capillaries. This mixture would con- 

 tain acid phosphates and chlorides. 



The mucous membrane of the stomach presents on its inner surface the 

 mouths of numerous microscopic tubes, which, like stockings, are some- 

 times single blind sacs, or, like gloves, terminate in several blind sacs like 

 the glove fingers. In the bottoms of these tubes, and along their sides, are 

 several closed spherical sacs or cells, containing other lesser sacs and fluid 

 within. The tubes, as a whole, dip down into the spongy tissue that underlies 

 the mucous coat, where they are surrounded by the fluid poured from the 

 network of nutritive capillaries, which fluid, as remarked above, contains 

 acid phosphates and chlorides. 



Now by pressure and osmosis a portion of this fluid will pass through 

 the walls of the gastric tubes, and the question is : 



Whether the fluid that goes through will contain free hydrochloric acid? 



The experiments I have made are conclusive on the principal point. 



By employing acid phosphate of lime and common salt I had this advan- 

 tage, that as increased acidity on the one hand is a just inference from in- 

 creased alkalinity on the other, and as increased alkalinity would be shown 

 by the precipitation of phosphate of lime (a visible white powder) I could 

 determine the qualitative fact without the difficulties and delay attending 

 on accurate quantitative analysis of the solutions, before and after the ex- 

 periments on both sides of the membrane. 



I employed an acid phosphate of lime of specific gravity 1*1 17, of a con- 

 stitution of 3(Ca O P 5 ) + 2P 5 , with an amount of phosphate of peroxide 

 of iron present as one to twenty-eight of the acid phosphate of lime. The 

 various other solutions employed were the ordinary laboratory reagents. 



On adding ammonia in small quantities to the solution of acid phosphate, 



