The determination of nitro-glycerine in simple dynamite No. 1 is easy; but not so when the dynamite contains substances soluble in ether, such as sulphur, resin, paraffin, and naphthalene.  After detailing at length the methods he employs, he concludes with the observation that the knowledge of the use of acetic acid—­in which nitro-glycerine dissolves—­for the determination of nitro-glycerine may be serviceable.  Mr F.W.  Smith[A] gives the following indirect method of determining nitro-glycerine in gelatine dynamite, &c.  About 15 grms. of the sample are extracted with chloroform in a Soxhlet apparatus, and the loss in weight determined.  In a second portion the moisture is determined.  A third portion of about 2 grms. is macerated with ether in a small beaker, the ethereal extract filtered, and the process of extraction repeated three or four times.  The united filtrates are allowed to evaporate spontaneously, and the residue warmed gently on the water bath with 5 c.c. of ammonium sulphide solution, and 10 c.c. of alcohol until the nitro-glycerine is decomposed, after which about 250 c.c. of water and sufficient hydrochloric acid to render the liquid strongly acid, are added, and the liquid filtered.  The precipitate is washed free from acid, and then washed through the filter with strong alcohol and chloroform into a weighed platinum dish, which is dried to constant weight at 50 deg.  C. The contents of the dish are now transferred to a silver crucible, and the sulphur determined.  This amount of sulphur, deducted from the weight of the contents of the platinum dish, gives the quantity of substances soluble in chloroform with the exception of the nitro-glycerine, moisture, and sulphur.  The amount of the former substances plus the moisture and sulphur, deducted from the total loss on extraction with chloroform, gives the quantity of nitro-glycerine.  Nitro-benzene may be detected, according to J. Marpurgo, in the following manner:—­In a porcelain basin are placed two drops of liquid phenol, three drops of water, and a fragment of potash as large as a pea.  The mixture is boiled, and the aqueous solution to be tested then added.  On prolonged boiling nitro-benzene produces at the edge of the liquid a crimson ring, which on the addition of a solution of bleaching powder turns emerald-green.  And nitro-glycerine in ether solution, by placing a few drops of the suspected solution, together with a drop or two of aniline, upon a watch-glass, evaporating off the ether, and then adding a drop of concentrated sulphuric acid to the residue, when, if nitro-glycerine is present, the H_{2}SO_{4} will strike a crimson colour, due to the action of the aniline sulphate upon the nitric acid liberated from the nitro-glycerine.

[Footnote A:  “Notes on the Analysis of Explosives,” Jour.  Amer.  Chem.  Soc., 1901, 23 [8], 585-589.]