400 Dr. Pearson’s Observations and Experiments 
white lac by fire; for 1800 grains of bees wax gave 1200 
grains of white butyraceous oil, with a little thin brown oil, 
and a very small quantity of water and acid ; and a very 
large quantity of hydrogen and carbonic acidgaz, with which 
was probably mixed nitrogen gaz; but an accident prevented 
me determining the presence of this last gaz. In the retort 
there remained only about ten grains of carbonaceous matter. 
The smell of the empyreumatic oils was very different from 
those of white lac. 
3. White lac appears to have the same kinds of affinity as 
bees wax ; but many of their combinations are so very diffe- 
rent in the two cases, as to determine white lac and bees wax 
to be different species of substances, although they agree with 
one another in more properties than they do with any other 
known bodies. As to the p£-la of the Chinese, we cannot 
judge of it unless a more particular account had been given of 
its qualities. 
4 . White lac and bees wax appear to be homogeneous 
substances, and to consist of the same kind of constituent parts, 
but the proportion of these parts is very different in the two 
substances; and hence the difference in the propert.es of bees 
wax and white lac. I consider the phosphate of lime, the 
soda, and muriate of soda, as extraneous to the composition of 
lac The different composition of the two substances may 
enable us to explain in a probable manner the different action 
of other bodies upon them. For instance, as it appears that 
a much greater proportion of carbon enters into the compo- 
sition of white lac than bees wax, the quantity of oxygen 
gaz in atmospheric air, applied under the usual circum- 
stances of combustion, is not sufficient to combine with the 
