Determining Volatile Substances. 



189 



this joint is sealed with paraffin e, as has been shown. The 

 apparatus is wiped, placed on the balance, and weighed. 



Upon removing the cap from the small tube in C, the reagent 

 runs from C into A. The volatile product is formed, is forced 

 upward through the drying column of calcium chloride, and 

 escapes through the annular space between B and C. When 

 the action ceases, a current of dry air is forced through C, to 

 drive all the volatile product from the apparatus, the cap is 

 then replaced, and the whole placed on the balance to be 

 weighed. The loss of weight represents the volatile product. 



The following results show the accuracy which may be 

 expected when carbonates are treated in the apparatus with 

 dilute hydrochloric acid : 



Table I. 

 Taken. Found. Error, 



grm. grm. grm. 







" 0-2000 







08*79 



—o-oooi 







0-2000 







0878 



— 0-0002 







0-2000 







0879 



—o-oooi 







0-2000 







0879 



—o-oooi 



Calcium 



\ 



0-5000 







2197 



— 0-0003 



Carbonate. 



0-5000 







2196 



— 0-0004 







05000 







2194 



— 0-0006 







0-5000 







2198 



-0-0002 







0-5000 







2197 



— 0-0003 







k 0-5000 







2197 



— 0-0003 







f 0-5000 







1134 



—o-ooii 



Barium 



\ 



0-5000 







1137 



— 0-0005 



Carbonate. 



0-5000 







1137 



— 0-0005 



* 





^ 0-5000 







1136 



— 0-0006 



Strontium 

 Carbonate. 





' 0-5000 







1485 



—0-0004 





0-5000 







1486 



— 0-0003 







' 0-5000 







1485 



— 0-0004 



In Table II are included the results of some experiments 

 made to determine the weights of hydrogen liberated by the 

 action of magnesium and zinc, upon dilute hydrochloric acid. 







Table II. 







Taken. 







Found. 



Error. 





grm. 







grm. 



grm. 





f o-iooo 







00087 



+ 0-0003 



Magnesium 

 Metal. 



| o-iooo 

 <( o-iooo 







0-0085 

 0-0084 



+ 00001 

 ±0-0000 





I o-iooo 







0-0084 



±0-0000 





[ o-iooo 







0-0083 



-o-oooi 





f 0-2000 







0-0061 



±o-oooo 





J 0-2000 







0-0062 



+ 0-0001 



Zinc Metal. 



{ 0-2000 







0*0062 



+ 0-0001 





| 0-2000 







0-0060 



—o-oooi 





I 0-2000 







0-0061 



±0-0000 



Am. Jour. Sci 



. — Fourth Series, 



Vol. 



XIX, No. 101.- 



—February, 1905. 



13 













