296 Notice of Gas from Cotton Seed. 
flame, but the gas speedily became more luminous, and 
continued of good quality until near the close of the ope- 
ration, when it began to burn with the blue flame of car- 
bonic oxide. 
It was obvious that, provided the experiment could be 
so managed as to convert the oily vapour, which came 
over undecomposed, into gas, the quantity of the latter 
would be increased and its quality improved. ‘That the 
oily vapour constituted no inconsiderable part of the 
whole product, was evident, not only from the appearance 
of the receiver, but also from the fact that the residuum 
weighed only ninety grains. This was pure charcoal, the 
seeds retaining their perfect form, and the tube being 
quite dry andclean. With the hope of decomposing this 
vapour, our next arrangement was as follows :-— 
Ex. 2. The same quantity of seed being introduced as 
before, the tube was laid horizontally across the furnace 
in such a manner, that the bottom containing the seed, pro- 
- jected into the open air, while the upper parts of the tube 
were raised to ared heat. As soon as the heat had so far 
reached the seed as to begin to expel oily vapour, the tube 
was drawn slowly forward into the furnace. A very abun- 
dant evolution of gas immediately ensued, greatly exceed- 
ing the product of experiment 1, though an accident 
prevented my estimating it accurately. In illuminating 
power, however, it was inferior to the former product,— 
a circumstance to be attributed, no doubt, to the effect of 
the upper part of the tube, (which was at a full red heat,) 
in decomposing the olefiant gas into the lighter carburetted 
hydrogen. These hints enabled me to manage this ex- 
periment more judiciously. 
Ex. 3. The same arrangement being made as in Ex. 2, 
the part of the tube within the furnace was slowly rais- 
ed to a/low red heat, and the oily vapour suffered to 
come into contact with it, as it gradually rose from the 
bottom of the tube, which was still remaining without the 
furnace. As the gas, however, began to fail, the tube was 
drawn very slowly forward as before, until it lay wholly 
within the furnace. This mode, it will be seen, was sugges- 
ted by that practised by the Messrs. Taylors of London, in 
manufacturing oil gas, when the oil is admitted into the re- 
torts kept.at a low red heat, drop by drop. This process 
