Liecke in Dingler’s Polytechnical Journal, prescribes the following formulæ for manufacturing the three several preparations, Mono-Nitro-Glycerin, Di-Nitro-Glycerin and Tri-Nitro-Glycerin. Mono-Nitro-Glycerin: Glycerin 100 grammes. Nitric acid, Sp. Gr. 1.3, 200 grammes. Dissolve the Glycerin in the nitric acid, and then add sulphuric acid 200 cubic centimeters. The product should be C³H⁵O²H} }O⁴ NO⁴H} Di-Nitro-Glycerin: Sulphuric acid containing 1 eq. water, two volumes, nitric acid, Sp. Gr. 1.4, one volume; mix the above, lower the temperature to 32°F, or below, and drop into it Glycerin, pure, one volume. Prod. C³H⁵O²H} }O⁴ 2NO⁴} Tri-nitro-glycerin: Sulphuric Acid, 3.5 parts. Nitrate of Potash, 1 part. cooled to 0°F, produces KO + 4SO³ + 6HO, from this the concentrated fuming Nitric acid is separated by decantation, and being maintained at 0°F, Glycerin 0.8 parts is very gradually added, producing C³H⁵O²NO⁴} }O⁴ 2NO⁴} From the above extracts of several of the most eminent chemists of the present day, the reader will glean, that in order to prepare this explosive, of uniform quality, invariable in composition, free from water, or any other impurity, it is not merely necessary to buy the best materials, but to have at command the means of verifying their purity before attempting its manufacture.