M. Berthelot gives the heat of formation of nitro-starch as 812 cals. for 1 grm., and the heat of total combustion as equal to 706.5 cals. for 207 grms., or for 1 grm. 3,413 cals.  The heat of decomposition could only be calculated if the products of decomposition were given, but they have not as yet been studied, and the quantity of oxygen contained in the compound is far from being sufficient for its complete combustion.  Berthelot and Vieille found the average velocities for nitro-starch powder, density of charge about 1.2, in a tin tube 4 mm. external diameter, to be, in two experiments, 5,222 m. and 5,674 m.  In a tin tube 5.5 mm. external diameter, the velocity was 5,815 m., and in lead tube 5,006 m. (density 1.1 to 1.2).  The starch powder is hygroscopic, and is insoluble in water and alcohol.  When dry it is very explosive, and takes fire at about 350 deg.  F. Mr Alfred Nobel has taken out a patent (Eng.  Pat.  No. 6,560, 88) for the use of nitro-starch.  His invention relates to the treatment of nitro-starch and nitro-dextrine, for the purpose of producing an explosive powder, to be used in place of gunpowder.  He incorporates these materials with nitro-cellulose, and dissolves the whole in acetone, which is afterwards distilled off.  A perfect incorporation of the ingredients is thus brought about.

Nitro-Jute.—­It is obtained by treating jute with nitric acid.  Its properties have been studied by Messrs Cross and Bevan (Jour.  Chem.  Soc., 1889, 199), and by Muehlhaeusen.  The latter used for its nitration an acid mixture composed of equal parts of nitric and sulphuric acids, which was allowed to act upon the jute for some time.  He found that with long exposure, i.e., from three to four hours in the acids, there was a disintegrating of the fibre-bundles, and the nitration was attended by secondary decomposition and conversion into products soluble in the acid mixture.  Cross and Bevan’s work upon this subject leads them to conclude that the highest yield of nitrate is represented by an increase of weight of 51 per cent.  They give jute the empirical formula C_{12}H_{18}O_{9} (C = 47 per cent.  H = 6 per cent., and O = 47 per cent.), and believe its conversion into a nitro compound to take place thus:—­

C_{12}H_{18}O + 3HNO_{3} = C_{12}H_{15}O_{6}(NO_{3})_{3} + 3H_{2}O.

This is equivalent to a gain in weight of 44 per cent. for the tri-nitrate, and of 58 per cent. for the tetra-nitrate.  The formation of the tetra-nitrate appears to be the limit of nitration of jute-fibre.  In other words, if we represent the ligno-cellulose molecule by a C_{12} formula, it will contain four hydroxyl (OH) groups, or two less than cellulose similarly represented.  The following are their nitration results:—­

Acids used.—­I.  HNO_{3} sp. gr. 1.43, and H_{2}SO_{4} = 1.84 equal parts. 
            II. 1 vol.  HNO_{3}(1.5), 1 vol.  H_{2}SO_{4}(1.84). 
           III. 1 vol.  HNO_{3}(1.5), 75 vols.  H_{2}SO_{4}(1.84).