various other useful Articles from Pit Coal. 339 
the neck into the receiver: this is the spirit of the tar, and 
with this spirit that first arises from the tar was the waiter 
japanned which I sent you. The reason I chose to have 
the receiver wider at the mouth considerably than the nose 
of the retort is, that there is a strong and very volatile oily 
ammonia, that does not soon condense, but gets out of the 
receiver into the air the instant it leaves the retort, and 
though but in a very small quanuty, so small that it ds 
hardly possible to catch it; yet will it impregnate the air for 
a great distance round, with its very penetrating smell, 
while the spirit. keeps dropping into the receiver pure and 
separate from the ammonia. The spirit is very volatile, 
quite as much so, if not more, than the spirit of turpen~ 
tine, and soon evaporates if exposed to the air, which is a 
proof of its drying nature; indeed when used as a substitute 
#or turpentine, it dries in the stove quite as soon or sooner, 
‘and takes equally as beautiful)a polish. I sent you three spe- 
cimens. No.1. 1s what came off the tar first. No, 2, is 
the same distilled a’ second time; and the third specimen 
is the second re-distilled again in a glass retort: it there 
leaves a little pitchy residuum, and comes over clear, as the 
sample. Very little of the spirit is lost in passing through 
these different stages, if care is taken that the fire is slow 
and the precess not hurried. When the sp.rit is perfectly 
extracted from the tar, there remains in the bason of the . 
retort that beautiful pitch or asphaltum sent, which when 
mixed with the spirit forms an ingredient for making the 
black varnish used in japanning. If it is wished to use it 
as pitch, less spirit must not be extracted from it. I find 
that six gallons of tar will produce, if care is taken, about 
two gallons or two gallons and a half of spirit. A great 
number of retorts may be kept working by a single man ; 
if we say only one hundred, and only worked down inva 
day, they will produce two hundred to two hundred and 
fifty gallons of spirit, so that, by increasing the number, 
any quantity may be obtained. When the spirit is used in 
the place of turpentine, the varnish-maker uses it in the 
same way, and in the same quantity, as there appears no 
manuer of difference in the use of it from spirit of turpentine 
in the making of varnish. When the asphaltum is used, 
it supplies the place of real asphaltum, and in about the 
same quantity. | have explained the whole as clear as I 
can ; but if any more information is required, I should feel 
happy in giving it, and am, sir, with great respect, 
Your obedient humble servant, 
Birmingham, March 13, 1810. . B. Cook. 
To C. Taylor, 4.D. Sec. Y2 LX. Com- 
