MANUFACTURE OF OXALIC ACID. 
67 
MATERIALS 
EMPLOYED. ATOMS. PRODUCTS. 
f Carbon 12 S 6 > 6 ^onic Acid. 
Common J { 9 \ 
Sugar <( Hydrogen 1 1 ] 2 V 
1 atom | \ — ?- 2. Water. 
[Oxygen 11 
f Nilroo-en 7 - — ^/C3-v— ^ 7 Deutoxide of Nitrogen 
1 C 14 
Nitric Acid<( n „_\ Jl' 
7 atnm, i Oxygen 35 < 12 xx 
7 atoms ^ ^ ^ & . ^ 3 Crystalized Oxal. Acid. 
These proportions do not greatly differ from those em- 
ployed in practice by oxalic acid-makers, when allowance 
is made for the loss of nitric acid incidental to their mode 
of manufacture. The following is the general proportion 
of materials employed : — 
Sugar - - - 112 lbs. 
Nitrate of potash - 560 lbs. 
Sulphuric acid, - - 280 lbs. 
which are said to produce 135 lbs. of oxalic acid, and 490 
lbs. of sulphate of potash or sal enixum. 
Experiment has proved to me that the first change pro- 
duced, is to convert the cane-sugar into grape-sugar, and as 
the first portions of gas evolved consist almost entirely of 
nitric oxide with little or no carbonic acid, it is clear that 
some compound is generated in the commencement of this 
process, which contains the elements of sugar united to an 
excess of oxygen — the above diagram must therefore be 
looked on as merely explanatory of the ultimate change. — 
Pharm. Jo urn. 
