Year: 1871

Of sulphur (puri6ed brimstone). In order
to make copperas, take iron nails, iron turn
ings. scraps, or any other pieces of iron,
and place them in water mixed with about
One-tenth Of sui phuric acid. A strong
boiling and foaming will result, and when
this ceases, let it stand for "a hours to set
tie. Then pour off the clear liquid and let
it slowly evaporate. You will see that
crystals of copperas will attach themselves
to the sides of the vessel or to stick or
string placed in the liquid.


If, however, you wish to perform this
same operation in such manner as to be
able to observe the whole theory of it, place
the iron scraps on the bottom A of wide
necked bottle B, and put water W on the
same, to fill the bottle about one-third or
fourth full. Then take well fitting cork
G, and make two holes in it by means Of a
ed-hot iron, a round file, or, better still


with a regular cOrk-borer, which is nothing
but cylinder Of thin brass, sharpened at
the end, and which cuts out a perfectly


round core. Make these holes of the same


size as the outside Of two glass tubes ID and


+, which are open at both ends. The first


D is drawn out above to a point Z, and


does not project far below the cork The


second K is made funnel-shaped at the top


Eff, and is pushed downward in the cork


50 that its lower end is immersed in the


water w. Now pour a little sulphuric


acid through the funnel-tube Eff, and YOU


will observe that as soon as it reaches the


iron below, an apparent boiling and


fOaming will commence. Now this ap-


parent boiling is nothing but the develop


mont of hydrogen gas, and as this cannot


escape but by the tube ID pat least if the


cork is tight and the glass tubes fit we'll


you will have an opportunity Of studying


the properties of this gas, and may collect
/. It IN bladder by first pressing all air out
; Of 1t and tying its neck around the exit-tube
I. Remember, however, that, when start
ing this experiment, the upper part Of the
glass bottle D filled with air, and that you
! must wait reasonable time to give the by
drOgen a chance to drive out this air, as a
J mixture of the two is explosive. Slight ac-


cldents have often happened to young stu


dents IN chemistry, when they applied a
flame to the tube z, il order to see if the


hydrogen was coming and if it would burn
Sometimes the stopper G with the glass
tubes Is thrown out, sometimes the bottle
. bursts, and sometimes the whole little ap-
7 paratus disappears, while tue pieces are
| atterward found scattered about the room
The reason that hydrogen is devclopc H.


that the iron cannot combine with the sui
, phurlc acid without being first oxydized OF
7 combined with oxygen. This oxygen j,
4 taken from the water in the bottle, which /.


decomPosed, and as it consists of two gaseOu,
, substances, oxygen and hydrogen, the by


drogen Is driven away as soon as the iror
takes hold Of the oxygen, because in chem
4 lstry the law Of the strongest prevails Ther
! the oxide Of iron combines with the sui
< phurle acid and forms what modern chem
lists call iron sui phate or ferric sul phate


and which IS nothing but so-called coppera
0 "a very inappropriate name, because ther,
o Is no copper about it. It was also callet
II green yltriOl-a much better name, becaus


II has green, vltreous appearance.