Lieut. Schmidt on some Kinds of Ftdminating Pffwder. 197 



The fluid is also an excellent solvent of caoutchouc, sur- 

 passing every other substance in this quality. It has already 

 been applied to this purpose. 



It will answer all the purposes to which the essential oils 

 are applied as solvents, — as in varnishes, &c. ; and in some 

 cases where volatility is required, when rectified it will far 

 surpass them. 



It is possible that, at some future time, when we better un- 

 derstand the minute changes which take place during the de- 

 composition of oil, fat, and other substances by heat, and have 

 more command of the process, that this substance, among 

 others, may furnish the fuel for a lamp, which remaining a 

 fluid at the pressure of two or three atmospheres, but becom- 

 ing a vapour at less pressure, shall possess all the advantao-es 

 of a gas lamp, without involving the necessity of high pres- 

 sure. 



Royal Institution, June 7, 1825. 



[In relation to the subject of this paper, see Phil. Mag. vol. Ivi. p. 455, 

 and Ivii. p. 3. — Edit.] 



XXVII. On some Kinds of Fulminating Potader itiflammable 

 hi) Percussion, and their Use in Fire-arms. By P. W. 

 Schmidt, Lieutenant in the Prussian Service.* 



\ POWDER inflammable by percussion has been used for 

 -^■*- some years past, especially in fowling-pieces. Thg fol- 

 lowing formulae have been given for the preparation of this 

 powder, the principal ingredient of which is chlorate of potash. 



1.) 100 parts of chlorate of potash (fulminating salt), 12 

 parts of sulphur, and 10 parts of charcoal are closely mixed. 

 The grains are produced by forcing the soft paste through a 

 sieve. 



2.) 100 parts of chlorate of potash, 42 parts of saltpetre, 

 36 parts of sulphur, and It parts of lycopodium. 



These arc the usual ingredients that have hitherto been 

 mixed witli the chlorate of potash for the purpose of making 

 priming powder. The guns, however, with which this powder 

 is used, are very various in their construction. In some it ex- 

 plodes of itself by means of the mechanism ofthelock,on being 

 cocked into a small conical recess, which comnmiiicates with 

 the touch-hole ; in others, it is put in previous to every shot. 

 In the former kind of guns a quantity of powder suflicient for 

 a certain number of shots is kept in a recess attached to the 

 lock, called a magazine; and the locks (which were invented 

 in Kngiand by Mr. Forsyth) arc called magazine-locks. 



• From Scliwcigger's Journal, Dancl xi. p. 66. 



In 



