Miscellanies. 385 
- The quantity of iron in this water is so great, as to produce, by 
the addition of nut galls, and a little gum arabic, a pretty good wri- 
ting ink. ‘The water is supposed to proceed from the decomposition 
of shale in its vicinity. —Edin. Phil. Jour. Apr. 1831. 
| xs, Platina Lamp.—In a communication from George Merry- 
weather, Esq. to Professor Jameson, dated Edinburgh March 5th, 
1831, it is proposed to extend the aphlogistic platina lamp, by con- 
structing the body of the lamp, of tin large enough to contain a 
quart or more of alcohol. This will be sufficient to keep the platina 
in a state of constant ignition for thirteen or fourteen days and nights. 
Such a lamp, while it is entirely devoid of glare, affords sufficient 
light to shew the face of a watch in the dark of night. It is best 
managed by inserting a little spongy platina into a small cage of 
platina wire. The top of the lamp wick should be spread out, a 
little, in the form of a coronet, and the wire cage pricked into it, so 
as to be nearly, but not quite, in contact with it. ‘The bottom of the 
lamp should be concave so that the wick may take up all the alcohol, 
and if it be connected with an unfailing reservoir of alcohol, the lamp 
may be kept ignited for years. The spongy platina does not appear. 
to be, in the nisin deteriorated by being kept in a state bs constant: 
ignition. 
- To prevent the access of dust, &c. the lamp is covered with a glass, 
shaped like ‘an inverted funnel, resting upon a ring or cylinder of tin 
having holes around it to admit,a current of air. if a light is requir- 
ed, the glass cover is to be elevated and the platina gently touched 
With a match of chlorate of potash, which will be instantly inflamed. 
Should the lamp diffuse an unpleasant odor in the room, a conden- 
sing shade or cover: may be applied to it, formed of tin. This cover 
is conveniently made of a conical shape. The base of the cone is 
to be convex inward, like the bottom of a common glass bottle. 
From the center of'this concave bottom (concave externally) a tube 
Proceeds downwards, of sufficient-length and diameter to admit the 
heck of the glass funnel which covers the lamp. ‘The vapors that — 
rise up through the funnel into the conical condenser, and fall to 
the bottom of it in a liquid state, may be drawn off through a stop 
Cock soldered to the edge of the cone. ‘This cone may be suspended 
aring to a nail in n the st and brought over the glass funnel when 
required. 
The author finds that equal parts of alcohol and whiskey answer 
quite as well as pure alcohol, or he says, one third of alcohol and two 
J ue tg 
. rc 
