SULPHURIC ACID MET WITH IN PRUSSIC ACID. 
219 
the different weights which have been brought 
forward, but without giving the sanction of 
the Association to them. He considered it 
proper that the algebraical formulae should 
be adhered to as far as possible. 
19. Mr. mallet SHEWED A BEAU- 
TIFUL WHITE MATERIAL PRE- 
PARED FROM TURF, WHICH WAS 
DECLARED BY A PAPER-MAKER 
TO BE PERFECTLY FITTED FOR 
THE MANUFACTURE OF PAPER. 
The upper stratum of turf, which covers 
immense tracts in Ireland, consists of layers. 
It is acted on by water to separate the 
leaves ; then by caustic potash or soda ; 
then by an acid. It is then bleached by chlo- 
ride of lime. During the process a substance 
is obtained possessing the odour of camphor, 
mixed with that of turpentine, which is fluid 
at 290*^ F. The upper stratum of turf may 
also be employed for mill boards, after being 
soaked in glue and pressed by a hydraulic 
press. 
Friday, \Ath August, 
20. Mr. DAVY DESCRIBED SOME EX- 
PERIMENTS WHICH HE HAD MADE 
IN REFERENCE TO THE RELATIVE 
VALUES OF VIRGINIAN AND IRISH 
TOBACCO. 
He procured nicotine by simply digesting 
the leaves in potash, and then distilling. A 
liquid possessing uniform qualities passed 
over. The liquid is acted on by acids, alford- 
ing salts possessing a sharp biting state. 
The effect of the liquid was tried upon differ- 
ent animals, and found to be highly narcotic. 
He found that 1 lb. of Virginian tobacco was 
equivalent to 2^ of Irish tobacco ; the root 
containing 4 or 5 per cent, of nicotine. The 
usual estimate of the relative values, by 
dealers, is as 1 to 2. 
21. Mr. SCANLAN DETAILED THE 
EXPERIMENTS WHICH HE HAD 
MADE UPON WHAT HE CONSIDER- 
ED A NEW FLUID, PREPARED 
FROM PYROLIGNEOUS ACID BY 
SATURATION WITH LIME, DIS- 
TILLATION AND PURIFICATION BY 
CHARCOAL. 
He found its boiling point to remain steady 
at 130° . The following table exhibits its pe- 
culiarities when compared with pyro-acetic 
and pyroxylic spirits. 
Sp. Gr. Boiling Point. 
Pyro-acetic. . 
. , *828 
150® 
Pyroxylic . . . 
. . *750 
140® 
New Fluid . . 
. . *906 
130® 
Another fluid was obtained likewise which 
appeared to be new, exhibiting a strong 
action with caustic potash. It was sug- 
gested, that the first fluid was acetate of 
methylene, the specific gravity of which is 
*919 and the boiling point 136®. The argu- 
ments of Mr. Scanlan were admitted by the 
Section to be conclusive, in favour of the 
substance being distinct from pyro-acetic, or 
pyroxylic spirits. 
22. Mr. moor MENTIONED A CURI- 
OUS CIRCUMSTANCE IN REFER- 
ENCE TO THE .CORROSION OF 
LEAD PIPES. 
The worm of a still used for preparing 
medicated waters, was exhibited, which was 
corroded completely through its substance, 
at those points where it had been supported 
with wood and tied with twine. At these points 
a black substance was formed, consisting of 
oxide and chloride of lead. It was obvious 
that the effect was to be attributed to galvanic 
action. 
23. Dr. barker DESCRIBED A NEW 
MODE OF SEPARATING THE PE- 
ROXIDE OF IRON BY MEANS OF 
ACETATE OF POTASH. 
The latter salt, when added to a solution 
of per- salt of iron, precipitates the peroxide 
when the liquid is boiled. This would appear 
to afford an elegant method of separating iron 
from manganese. 
^ He made an observation relative to the pre- 
cipitation of magnesia by phosphate and car- 
bonate of ammonia: viz. that the same 
precipitation takes place with bi -carbonate 
of potash, and other salts. 
24. Dr. GEOGHEHAN SUGGESTED 
THEADVAN PAGE OF EMPLOYING 
THE DOUBLE SALT OF IODIDE 
OF POTASSIUM AND BICYANIDE 
OF MERCURY, FOR THE PUR- 
POSE OF DETECTING MURIATIC 
ACID IN PRUSSIC [ACID. 
Sulphuric acid is frequently met with in 
prussic acid, but the distinction between 
these two acids is readily made, by means 
of nitrate of barytes. The peroxide of mer- 
cury usually employed for testing the purity 
of prussic acid is ambiguous in its action, 
as it is usually impure. The use of this salt 
is not applicable to the alcoholic prussic acid. 
25. Mr. JOHNSTON MADE SOME 
OBSERVATIONS ON THE IODIDES 
OF GOLD, WHICH HE HAD ANA- 
LYZED. 
Their composition is similar to the chlo- 
rides. Previous errors, he found, were to be 
ascribed to the precipitation of an excess of 
gold, when ammonia was employed in the 
analysis. 
There are three compounds, viz. (i.) Au 
I ; (2.) Au 3 I ; (3.) Au 3 I -f- K I, the atom 
of gold being 25. 
26. Dr. william BARKER MADE 
SOME OBSERVATIONS ON THE 
PASSAGE OF ELECTRICITY A- 
LONG A PLATINUM WIRE. 
Black spots were observed at regular dis- 
tances, the rest of the wire being luminous. 
