262 
LEEDS CHEMISTS’ ASSOCIATION. 
moves more than 5 per cent, from a sample of wax, it may be set down as containing 
resin. Spermaceti, paraffin, and caraauba wax lose very trifling amounts; stearic acid 
loses nearly two-thirds. 
3. The ether test for Japan wax, spermaceti, stearic acid. (Chem. N. vol. v. p. 170.) 
M. Eobinaud says that pure bees’-wax treated with fifty times its weight of ether, 
leaves just fifty per cent, residue. 
Experiments.—Thirty grains treated with ether. 
Residue. 
Nos. 1 & 2. Standard bees’-wax 16*6* in each case 
3. Block white wax 15‘0 
4. Cochin „ „ 15 - 4 
The author’s statement as to the behaviour of genuine wax is consequently correct. 
To proceed further, he states that suet, stearic acid, and vegetable wax dissolve almost 
entirely in ether, and that vegetable wax leaves only five per cent, insoluble. 
Experiments.—Thirty grains Japan wax. 
30 grains 
(Block) “G” 
Residue. 
11-5 
(Block) “ B ” 
(Cake) “ H ” 
10-8 
8-2 
Spermaceti ... 
0* 
?? 
Stearic acid ... 
0- 
5? 
Carnauba Avax 
26-7 
Here a discrepancy is apparent between these results and the statements of the author. 
Experiments with mixtures. 
Residue. 
30 grains of wax -j- Japan wax ~ 9’6 
00 40 (vice 9 grs.) 
30 grains of wax -f- stearic acid = 6 - 3 
60 50 (vice 7*5) 
30 grains of wax -j- spermaceti = 11* 
80 20 (vice 12) 
30 grains of round cake-wax = 3’3 
It is especially interesting to note that the discrepancies so striking when t, 
terant substances only were treated with ether, are much mitigated when mi 
these matters with pure wax are the objects of inquiry. x . ,, 
With each result is stated the amount that should have been left, if M. Rob mau s 
test had been quantitatively reliable. Of course, in all these cases had pure wax been 
the object examined, the residue would have been fifteen to sixteen grains. The results 
obtained would justly have condemned every specimen. The instance of round white 
wax especially deserves notice. The test would indicate only twenty-two per cent, of 
pure wax (!), and seventy-eight of something else. Other tests show that this is sper¬ 
maceti. It is not stearic acid, the so-called “ stearine ” of trade. But the test is not 
quantitatively absolute. A mixture of pure wax with either spermaceti or Japan wax, 
does not behave the same as if they were separately treated by the same solvent. When 
spermaceti is present, less residue is obtained from the portion of genuine Avax than should 
be the case. 
With Japan wax, the amount of adulteration is correctly shoAvn, and the Japan wax is 
really dissolved without residue, although in its pure form it left thirty to forty per cent. 
This has apparently escaped the author, but it affects the value of the test vitally. The 
fact that such substances may re-act Avhen they meet in the presence of a solvent must 
be recognized in future. Still, the ether test appears to be one of very great value, 
detecting nearly all adulterations qualitatively, and giving approximate ideas of their 
amo nt. 
4. Borax test. f—Hager states that the presence of Japan wax may be detected by 
its behaviour with a boiling solution of borax. In such solution, bees’-wax is nearly 
* This tested for sugar, left *4 per cent, of Sugar, 
•j* Chem. News, vol. v. p. 84. 
