320 LABORATORY GUIDE IN PHYSIOLOGY. 



for any purpose, a chronograph be removed from a 

 table when the system is in operation, the general 

 circuit must be instantly completed by use of a con- 

 nector. 



17. To prepare 10% hydrochloric acid, the acidum hydro= 

 chloricum dilutum of the U. S. P. 



The concentrated, c.p., hydrochloric acid of a sp. gr. 

 of 1.16 contains 31.9 per cent by weight of HC1 gas. To 

 prepare 10% HC1, take 31.4 c.c. of the concentrated acid 

 and dilute with distilled water to 100 c.c. From this di- 

 lute HC1. 0.2% HClorO.1% HC1 or any other desired 

 strength below 10% may be readily obtained. 



