Substances in the Wet Way. 



375 



carbonate — which was effected by treatment with an excess of 

 barium hydroxide and filtering. An excess of potassium per- 

 manganate is then run into the flask and the solution heated to 

 boiling. An excess of dilute sulphuric acid is introduced into 

 the mixture and the carbon dioxide, thus set free, completely 

 driven over to the absorption flask and determined as before. 

 Table II shows results obtained by the process. 



Table II. 





Barium 











Error 





formate 



Ba0 2 H 2 



Ba0 2 H 2 



C0 2 



C0 2 



on 





taken. 



taken. 



found. 



found. 



calculated. 



C0 2 . 





grm. 



grm. 



grm. 



grm. 



grm. 



grm. 



1. 



0*5001 



0-9302 



0-1745 



0-1939 



0-1935 



0*0004 + 



2. 



0*5033 



0-9012 



0-1402 



0-1953 



0-1947 



0-0006 + 



3. 



1-0002 



1-6861 



0-1793 



0-3867 



0-3870 



0-0003 — 



4. 



1-0059 



1-6279 



0-1093 



0-3897 



0-3892 



0-0005 + 



5. 



1-3750 



2-2529 



0-1820 



0-5315 



0-5320 



0-0005 — 



6. 



1-5028 



2-4419 



0-1754 



0-5816 



0-5814 



0-0002 + 



These results show plainly that the carbon of formic acid 

 may be determined accurately by the method outlined. 



It was found incidentally that ammonia cannot take the 

 place of the sodium hydroxide in this process, probably because 

 the ammonia volatilizes to the absorption flask during the boil- 

 ing and is acted on by the iodine subsequently used and is thus 

 registered as barium hydroxide. 



It is a well-known fact that tartrates are oxidized by per- 

 manganates. I have found, however, that when tartaric acid 

 is treated under the conditions of analysis outlined above in 

 acid solution, the oxidation is incomplete ; but that oxidation 

 is complete if the tartrate is heated in a solution alkaline with 

 sodium hydroxide and then acidified with sulphuric acid. 



The tartrate used was a recrystallized tartar emetic, dried at 

 100° C. The following results were obtained with such a tar- 

 trate by this process. 



Table III. 





Tartar 











Error 





emetic 



Ba0 2 H 2 



Ba0 2 H 2 



co 2 



C0 2 



on 





taken. 



taken. 



found. 



found. 



calculated. 



C0 2 . 





grm. 



grm. 



grm. 



grm. 



grm. 



grm. 



1. 



0-5051 



1-2450 



0-1709 



0-2756 



0-2751 



0*0005 + 



o 



0-5030 



1-2226 



0-1536 



0-2743 



0-2739 



0-0004 + 



3. 



0-7509 



1-7355 



O-1401 



0-4094 



0-4091 



0-0003 + 



4. 



0-7541 



1-7430 



0-1410 



0-4111 



0-4107 



0-0004 + 



5. 



1-0018 



2-3456 



0-2187 



0-5458 



0-5456 



0-0002 + 



6. 



1-0005 



2-2435 



0-1196 



05451 



0-5450 



0-0001 + 



Am. Jour. Scl— Fourth Series, Yol. IV, No. 23. 

 26 



-Nov., 1897. 





