Blasting gelatine is made by dissolving gun cotton (collodion wool, nitro-cellulose) in nitro-glycerin. Both are pressed into cartridge shape.
Nitro-glycerin itself is a strong poison which can be absorbed both through the skin and from the alimentary canal. Kobert describes a case where the rubbing of a single drop into the skin caused symptoms lasting for ten hours. Workmen engaged in washing out nitro-glycerin from the kieselguhr earth, having in doing so their bare arms immersed in the liquid, suffered. Although it be granted that nitro-glycerin workers become to a large extent acclimatised, cases of poisoning constantly occur in explosives factories referable to the effect of nitro-glycerin.
Persons mixing and sieving dynamite suffer from ulcers under the nails and at the finger-tips which are difficult to heal. Further, where the apparatus employed is not completely enclosed nitrous fumes escape and become a source of danger. Formerly this danger was constantly present in the nitrating house where nitration was effected in open vessels. Now that this is usually done in closed nitrating apparatus with glass covers the danger is mainly limited to the acid separating house, wash house, and especially the room in which denitration of the waste acids is effected.
Fig. 10.—Preparation of Nitro-glycerin. Nitrating Vessel (after Guttmann)
A Glycerine reservoir; C Fume flue; D Acid supply pipe; E, G Compressed air supply; H, J Cooling coil.
A fatal case in a nitro-glycerin factory was reported in 1902 where, through carelessness, a separator had overflowed. The workman who tried to wash away the acid with water inhaled so much of the nitrous fumes that he succumbed sixteen hours later.
Other cases of poisoning by nitrous fumes occurring in the denitrating department are described in detail in the section on the use of nitric acid.
One of these occurred to a man forcing dilute nitric acid from an earthenware egg by means of compressed air into a washing tower. The egg burst and broke an acid tank. The workman died on the following day.
A fatal case occurred in a dynamite factory in cleaning out a storage tank for waste acid in spite of previous swilling and ventilation.