68 
THE BLOW PIPE IN PRACTICAL CHEMISTRr. 
Uiat, if A be made enormously large, it will 
not only require a considerable quantity of 
water for its supply, and a long period to fill ; 
but the whole machine will, thereby, be ren- 
dered extremely unwieldy and inconvenient. 
It may, too, perhaps, be as well to state, that, 
in order to economise the water as much as 
possible, it may be conducted as it flows from 
the cock at M, by means of a pipe or other- 
wise, to a vessel appropriated for its recep- 
tion, from which it may be again transferred 
to the cylinder A when required. 
W. H. O. 
ON THE PRACTICE OF THE BLOW- 
PIPE. 
Dear Sir, — Among the numerous contri- 
butions which have at various periods ap- 
peared in your pages relative to the con- 
struction and management of blow-pipes, 
I have been surprised at not finding any 
directions for the practice of the moiith 
blow-pipe; an instrument far exceeding, in 
utility and convenience, all the artificial 
combinations wliicb have been invented to 
supply its place. Thinking, therefore, a 
communication on the subject likely to 
prove interesting to your chemical readers, 
and calculated to promote the employment 
of this useful little instrument, I am in- 
duced to solicit your insertion of the fol- 
lowing practical, though somewhat desul- 
tory, remarks, and am, 
Yours, very truly, 
Libertus, 
Newington, March 9 , 1835. 
The introduction of the use of the blow- 
pipe in practical chemistry may be regarded 
almost in the same light as the application 
of the power of steam to the purposes of 
commerce. If the latter has increased our 
national resources, and forwarded the in- 
terests of mechanical science, by economis- 
ing the labour and expenditure which were 
formerly bestowed— the former has in like 
manner advanced the cause of chemistry 
and its dependent sciences, by reducing the 
expense of fuel, time, and material, which 
were originally required in qualitative ana- 
lysis. If the mechanic can now produce, 
with comparative ease and expenditure, an 
article which, before the introduction of 
the steam-engine, would have required the 
labour of many weary days, and the con- 
sumption of much valuable material — the 
modern chemist can, with equal facility, 
detect the constituent principles of a body 
which, before the invention of the blow- 
pipe, would have called in requisition the 
unremitting exertions of many tedious 
nights, and the profuse employment of ma- 
ny rare and, perhaps, valuable substances. 
In fact, by the introduction of this simple, 
yet invaluable, instrument, the modern 
chemist can, by his parlour fire-side, and 
with a common candle, perform those ope- 
rations, to accomplish which the ancient 
and less gifted philosopher would have been 
compelled to resort to the unhealthy atmos- 
phere of a laboratory, and the continued 
poring over an intensely active fire. The 
blow-pipe, according to Bergman, had been 
long employed in the arts by jewellers and 
others, for the purpose of soldering, be- 
fore it was applied to the purposes of ana- 
lytical chemistry and mineralogy, by a 
Swedish metallurgist of the name of Sual, 
about the year 1733. This individual ap- 
pears, horvever, to have left no written ac- 
count of the methods which he adopted in 
its application. The researches of Cron- 
stedt, Bergman, and Gahn, — and, more re- 
cently, those of Berzelius and Faraday, 
have concurred in raising this instrument 
to the eminent station of utility which it at 
present enjoys. In the work of Berzelius 
on this subject, will be found ample in- 
structions for the pursuit of mineralogical 
and analytical chemistry ; and in the Che- 
mical Manipulations” of Dr. Faraday, the 
student will meet with copious directions 
for applying this instrument in the bend- 
ing and blowing of glass, in practical che- 
mistry. For the former purpose, the 
mouth blow-pipe possesses undeniable ad- 
vantages ; but for the more fatiguing ope- 
rations of the latter, the table or hydros- 
tatic blow-pipe will he found convenient. 
The advantages possessed by the mouth 
blow-pipe over all those instruments, whose 
blast is produced by artificial means, con- 
sists in its portability, economy, and the 
facility of immediately suspending or modi- 
fying the blast. “ The chemist does not 
possess,” says Dr. Faraday, “ a more 
ready, powerful, and generally useful in- 
strument than the mouth blow-pipe, and 
every student should early accustom himself 
to its effectual use and application.” 
The supply of a continued stream of air is 
the chief difficulty which a beginner ex- 
periences in learning the use of this in- 
strument ; and this difficulty is, I appre- 
hend, not unfrequently increased by the 
employment of a blow-pipe with too large 
an orifice, in the first instance. The fol- 
lowing method of constructing will, I have 
reason to believe, be found more efficacious 
than any other hitherto published, since I 
have by its means succeeded in less than 
halfanhourin communicating the art of 
blowing to a class of several persons. Let 
the pupil procure a tube of glass, h e about 
13 inches long, and ot the size and thick- 
ness of a. Let him now thoroughly heat 
the tube at c, about two inches from the 
end, by slowing turning it round in the 
flame of a candle, or, what is better, a 
spirit lamp. When he find that it will 
yield, let him bend it gradually till it has 
acquired the position represented by fig, 2. 
