Sub stances in the Wet Way. 



379 



Table IV. 





Substance 



Ba0 2 H 2 



Ba0 2 H 2 



C0 2 



C0 2 



Error on 





taken. 



taken. 



found. 



found. 



calculated. 



C0 2 . 





grm. 



grm. 



grm. 



grm. 



grm. 



grm. 







Analysis of ammonium oxalate. 





1. 



0-5009 



1-3534 



0-1469 



0-3097 



0-3101 



0-0004 — 



2. 



0-5006 



1-3400 



0-1308 



0-3103 



0*3099 



0-0004 + 



3. 



0-5005 



1-3400 



0-1343 



0-3094 



0-3098 



0004 — 



4. 



1 -0002 



2-5460 



0-1347 



0-6188 



0-6192 



0-0004 — 



5. 



1-0010 



2-5192 



0-1094 

 Analysis of 



0-6185 

 cane sugar. 



0-6197 



0-0012 — 



1. 



0-2001 



1-3926 



0-1905 



0-3085 



0-3088 



0-0003 — 



2. 



0-2000 



1-3926 



0-1936 



0-3077 



0-3086 



0-0009 — 



3. 



02001 



1-3926 



0-1857 



0-3097 



0-3088 



0-0009 + 



4. 



0-2014 



1-3400 



0-1279 



0-3111 



0-3108 



0-0003 + 



The results are evidently very satisfactory. 



The Determination of the Oxygen required to Oxidize an Organic 



Substance. 



Several different methods have been proposed for estimating 

 the oxygen present in organic substances, depending, in gen- 

 eral, upon the determination of the oxygen which must be 

 supplied to burn the substance to a known amount of carbon 

 dioxide and water — thus discovering by difference the oxygen 

 originally contained in the substance. Lavoisier is said to have 

 measured directly the oxygen used in burning organic sub- 

 stances ; Gay-Lussac and Thenard determined the oxygen used 

 by measuring the amount of potassium chlorate reduced by 

 burning the organic compound; Baumhauer* determined the 

 oxygen used by measuring the volume of oxygen entering the 

 combustion furnace and subtracting the measure of the gas 

 coming from the combustion tube, which was set up according 

 to the well known method for determining carbon and hydro- 

 gen ; Stromeyerf determined the amount of copper reduced by 

 the ignition of the substance in copper oxide ; LadenburgJ 

 oxidized the substance by heating in a sealed tube with a 

 known amount of iodic acid, determining at the end of the 

 operation the amount of iodic acid left ; Mitscherlich§ has 

 estimated the oxygen in organic substances directly by decom- 

 posing the substance by ignition in a stream of chlorine gas, 

 estimating the oxygen content by determining the resulting 

 carbon dioxide and monoxide. 



As it has been shown in the work described that carbon may 

 be determined in organic substances by oxidation with chromic 

 and sulphuric acids without the evolution of oxygen gas, it 

 would seem that the determination of the oxygen in the sub- 



* Ann. Chem. Pharm., xc, 228. % Ann. Chem. Pharm., cxxxv, 1. 



f Ann. Chem. Pharm., cxvii, 247. § Pogg. Ann., cxxx, 536. 



