Nluminating Gas jrom Cotton Seed. 363) 
lumination quite equal to that of the oil gas, (of which it is in- 
deed only a variety,) and superior to most varieties of the bitu- 
minous coals. It was inferior to the pure olefiant gas and 
this is the fact with the inflammable gases obtained from per- 
haps every substance except alcohol decomposed by sulphu- 
ric acid. The kernel of the hickory-nut comes the nearest 
to the olefiant and is but little inferior ; the quality of the gas 
is considerably debased by using the entire nut—the woody 
covering of which affords a gas which burns with a paler 
flame. | 
Itis very easy to injure the gas of cotton seed by a careless 
management of the heat, particularly by using too much heat, 
but this is true, prebably, of all other substances which af- 
ford inflammable gases ; in general the lower the heat, pro- 
vided it be sufficient, the better the gas. 
The following remarks were furnished by Professor Olm- 
sted at our request.—EpiTor. 
_ Cotton seed is highly oleaginous, and the object in my 
arrangements for obtaining the gas, is to bring the oily va- 
pour, (which is expelled by a very gentle heat) into contact 
with a surface of ignited iron, by which it is decomposed into 
carburetted hydrogen gas. For this purpose, a heat not 
exceeding the lowest degree of redness, is all that is necessary, 
If it be carried higher, a lighter kind of gas is produced, 
which is greatly inferior to the other in illuminating power. 
A furnace of brick work, or even a common culinary fire, 
will afford therefore the requisite degree of heat. My meth- 
od of proceeding has been as follows: 
‘61. An ounce of cotton seed ts dried on the fire in a ladle, 
and a red hot iron is introduced to singe off the small remnant — 
of cotton that adheres to the seed. [t is dried, because the 
moisture, by its decomposition, would produce an inflamma- 
ble gas, not sufficiently luminous for our purpose, and it is 
singed for a similar reason, the gas produced by the cotton 
being inferior to that of the seed. : 
“ 2. ‘Thus prepared, the seed is introduced into an iron 
tube closed at one end like a gun-barrel, and is pushed down 
quite to the bottom of the tube by a ramrod. 
3. The tube isnext laid acrossa farnace (a common fire 
would answer) in such a manner, that the closed end of the 
tube containing the seed, projects out of the furnace so far, 
that the seed may be removed entirely from the direct actien 
