On the late trial of Dr. Simon Bernard, in London, for conspiracy to murder Louis Napoleon, some very interesting scientific information was elicited in the testimony regarding fulminating powder. J. D. Parker, a druggist, testified that Bernard on the 14th of November, 1857, bought of him 8 pounds of absolute alcohol, 10 pounds of pure nitric acid, and 1 pound of quicksilver, which were the exact proportions for making fulminating quicksilver. C. Nicholson, chemist, engaged in the manufacture of fulminating powder for the government, testified that the ingredients and proportions for making fulminating mercury were 1 part by weight of mercury, 8 of absolute alcohol, and 10 of pure nitric acid. In order to make this powder, the mercury is first dissolved in nitric acid, and the solution thus obtained is added to the alcohol. When this is effected, a violent reaction ensues, accompanied with evolved masses of white vapor, and the fulminating mercury is precipitated in the form of a dense powder varying from a white to a gray and a yellow brown color, but the white is the purest and strongest. It is more explosive than gunpowder when dry, but it is kept prepared in a wet state, when it is perfectly harmless. M. C. Picot, director of the chemical laboratory connected with the artillery department in Paris, testified that the powder of the shells or grenades employed in the assassination act in Paris was pure fulminating mercury. He had examined their contents and was sure of this. W. Tozer, of the artillery works of the Woolwich arsenal in England, testified that fulminating mercury was twenty times stronger as an explosive agent than gunpowder. This he had proved by experiments with shells.