164 Miscellaneous Intelligence. 



essay on the following subject. To shew by decisive experi- 

 ments if the violet ray of the solar spectrum possesses the 

 virtue of communicating magnetism to the unmagnetized needle 

 of steel ; if this virtue belongs to it, to the exclusion of the 

 other coloured rays — and, in short, if this species of communi- 

 cated magnetism, attributed to the violet light, is real or illusory- 

 It is stated, that Professor Configliachi, found magnetism was 

 communicated by every other ray of light. — Memoires to be sent 

 to MM. Mollet and Dumas, before July, 1823. 



21. Inflammation of Po-coder under Water. — M. Serullas has 

 given the following directions for the preparation of a very ful- 

 minating charcoal, by means of which, gunpowder may very 

 readily be inflamed under water. 



Carefully powder together 100 parts of tartar emetic, and 3 

 parts of lamp black, or common charcoal. Prepare some cruci- 

 bles, capable each of holding about 2 ounces of the mixture, by 

 rubbing them within with powdered charcoal to prevent the 

 adherence of the carbonaceous mass left after calcination. Fill 

 them about three-fourths with the mixture, then put in a stratum 

 of powdered charcoal, and lute on a cover; after 3 hours' calci- 

 nation in a good reverberatory furnace, the crucibles are to be 

 removed, and left for six or seven hours to cool, that the air, 

 ■vvhich always enters, may have time to burn the surface of the 

 fulminating mass, for otherwise, if withdrawn too soon, explo- 

 sion always takes place. At the end of that time great care is 

 to be taken in transferring the mass in the crucible as rapidly 

 as possible into a vessel with a large aperture, which can be 

 perfectly closed. In time, the mass divides of itself into frag- 

 ments, and may be preserved for years. 



When the calcination has been thus performed, the produce 

 is excessively fulminating ; so as, without compression or confine- 

 ment, to give, on the contact of water, a detonation like that of 

 a powerful musket. 



The following mixture will also produce an equally fulminat- 

 ing charcoal; 100 parts of antimony, 75 of cream of tartar, 12 

 of lamp black, well powdered and mixed together. 



The experiment of firing gunpowder under water by means 

 of these substancef, was made in the following manner: — half 

 an ounce of gunpowder was put into a strong glass tube, closed 

 at one end ; a piece of fulminating charcoal, about the size of 

 a pea, was placed upon it, and immediately the orifice of the 



