174 LAB OR A TOR Y G U1DE IN PHYSIOL OGY. 



stomach? May any of the above acids serve as 

 digestives and as foods? 



As digestives and as tonics? 

 As digestives, foods and tonics? 

 Cite authorities. 



(7) To determine the optimum strength of the hydro- 

 chloric acid. 



Prepare with care the following three dilutions of 

 hydrochloric acid: 10%, 1%, 0.1%. [See Appendix 

 A, 17.] 



Into twelve test tubes put as many small masses 

 of fibrin; into each tube put 1 c. c. of neutral 10% 

 dilution of glycerin extract of pepsin. Label and fill 

 tubes as follows: 

 Tube (a) 5%: Add to the fibrin 5 c. c. of 10% HC1 



and of distilled water a quantity sufficient to make 



10 c. c. 

 Tube (b) 2%: Add 2 c. c. of 10% HC1 and aqua dist. 



q. s. ad 10 c. c. 

 Tube (c) 1%: Add 1 c. c. of 10% HC1 and aqua dist. 



q. s. ad 10 c. c. 

 Tube (d) 0.5%: Add 5 c. c. of 1% HC1 and aq. dist. 



q. s. ad 10 c. c. 

 Tube (e) 0.4%: Add 4 c. c. of 1% HC1 and aq. dist. 



q. s. ad 10 c. c. 

 Tube (H 0.3%: Add 3 c. c. of 1% HC1 and aq. dist. 



q. s. ad 10 c. c. 

 Tube (g) 0.2%: Add 2 c. c. of 1% HC1 and aq. dist. 



q. s. ad 10 c. c. 

 Tube (h) 0.1%: Add 1 c. c. of 1% HC1 and aq. dist. 



q. s. ad 10 c. c. 

 Tube (j) 0.05%: Add 5 c. c. of 0.1% HC1 and aq. dist. 



q. s. ad 10 c. c. 



