The authors commenced with an account of the trials they made with the Cyanide of lead; which, according to Dr Brown's most recent announcement, is resolved by his process into gaseous nitrogen and silicon. In the first place, however, they could not succeed in obtaining a pure cyanide of that metal. For whether they decomposed the cyanide of potassium, or the hydrocyanate of ammonia containing an excess of hydrocyanic acid, by neutral acetate of lead, by this salt acidulated with acetic acid, or by tribasic acetate, they constantly obtained a compound containing a large quantity of a hydrated basic acetate of lead; and they were not more successful when they substituted other salts of lead for the acetate as a precipitant, such as the nitrate, basic nitrate, nitrite, chloride, or iodide.