54 REDTENBACHER ON THE COMPOSITION OF STEARIv 
C. H, O. 
2 equiv. Anhydrous stearic acid 136 . . 132 . . 10 
1... Oxide ofzthyl. . . Ay} ein’ fe alted 
Digieeeu WV ACER a) ke 46 oT ve O3\.02}3 3 (ies pa ed 
C 140 H 140 O 14 
and from this the following results may be deduced :— 
Found. Equiv. Per cent. 
arbor) 5:7 7°17 6+ «¢ A404,,6, f,,1.10700°9. aaa 
Favadrogen > 12°84.) +.) 2«N4@ <6),5) 1174771, eae 
Weyeen. 3=298D 2 Id .. - 14000 ees 
100°00 13848°0 100°00 
The stearate of soda was prepared by boiling the hydrated 
stearic acid with an excess of carbonate of soda, expressing and 
drying the salt thus obtained ; this was now dissolved in alcohol, 
the solution filtered, treated with water, evaporated and dried on 
a water-bath. 
1:500 gr. of this salt gave 0°2685 gr. carbonate of soda, or 10°51 
per cent. of caustic soda; calculation gives 10°70 per cent. 
Again, 0°3855 gr. of the substance yielded 0:969 gr. carbonic 
acid, and 0°390 gr. water ; these represent in 100 parts, 
Carbon «6° 4.54° 3): "SRS9 
Hydrogen . . . .° 11°24 
The theoretical composition requires 
Oarbon. outs kebton sekuiel a 
Hydrogen... ~ 11°30 
Now supposing the whole of the soda contained in the 0°3855 
gr. of the substance = 0°040 gr. to have remained behind in the 
combustion tube as carbonate of soda, then it is evident that the 
quantity of carbonic acid thus remaining would be 0029 gr., 
which would raise the per centage of carbon to 71°59, and thereby 
render the result erroneous ; since, however, in combustion with 
oxide of copper the whole of the carbonic acid never remains be- 
hind, but nearly one third of it passes off, the per centage of 
carbon is only raised from 69°49 to 70°87, which also agrees with 
the theoretical composition. 
