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 arable, a pretty good wri- 

 ting ink. The water is supposed to proceed from the decomposition 

 of shale in its vicinity. — Edin. Phil. Jonr. Apr. 1831. 



5. Plaiina 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 least, deteriorated by being kept in a state of 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 

 neck 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 

 by a ring to a nail in the wall, 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 



