Part 19

=HELAGON= is a German perchlorate explosive made by the Köln-Rottweil Pulverfabriken. It contains not more than 10 per cent. of potassium perchlorate, not more than 5 per cent. of zinc-aluminium alloy, aromatic nitro-bodies and neutral nitrates, excepting those of potassium and barium. It may also contain flour or potato meal and neutral substances.

=HELIT= is a similar explosive to Helagon, except that it contains dinitro-chlorhydrin, not more than 6 per cent., in the place of the zinc-aluminium alloy.

=HELLHOFITE=} =HELLITE=} are different names for what is practically the same explosive of the Sprengel type. It consists of a mixture of strong nitric acid and various nitro-compounds, e.g.--

Dinitro-benzene 1 Nitro-benzene 1 Nitric acid 1·5 Nitric acid 2·5

A form of this explosive was tried by Gruson as a charge for shell many years ago. See also Panclastite.

=*HENRITE= is a smokeless shot-gun powder of the fibrous 33-grain bulk type. A sample examined in 1902 had the composition--

Nitrocellulose, insoluble 71·0 ” soluble 7·1 Metallic nitrates 7·5 Nitro-compounds 7·6 Paraffin 5·5 Moisture 1·3

=HERCULES POWDER.=--The name of a brand of American dynamite.

=HERCULITE.=--This name has been given to several explosives. One was a mixture of sawdust, camphor, potassium nitrate and other substances, which was used for blasting. There was a coal-mine explosive of this name on the Permitted List, made by the British Explosives Syndicate, Ltd.--

Date of Permit 22-6-14

Nitroglycerine 33 Collodion cotton 1 Potassium perchlorate 27 Wood meal 10 Ammonium oxalate 29

Limit charge 16 oz. Power (swing of ballistic pendulum) 2·72”

but the permit has been repealed.

=HIMALAYITE.=--A high explosive made from potassium chlorate, potato starch and a drying oil. The chlorate and starch are first heated together with water, and when dry the oil is mixed in. The explosive is said to have been adopted by the Portuguese for filling shell. It passed the chemical tests in England, but no licence was taken out for its manufacture.

=HUDSON’S EXPLOSIVE.=--A stiff blasting gelatine made by incorporating nitroglycerine and collodion cotton together with the aid of acetone. It was tried in America in 1889 for filling shell, but is not used now for this purpose.

=HYGRADE COAL POWDER NO. 2= is an American coal-mine explosive on the Permissible List. It is a nitroglycerine explosive.

=*IDEAL POWDER= is a shot-gun powder made by Nobels.

=IMPERIALITE= is of no practical importance, but is interesting, as its history is that of the explosive one meets in the comic papers. The Marquis R. Imperiali had large private means and some knowledge of chemistry. He took out patents for a number of explosive mixtures and built a small factory in N. Italy, which started work in 1911. An explosion occurred the first day and killed five of the fifteen workers. Imperiali escaped and re-erected his factory. The day after it was restarted it blew up again and Imperiali was killed. The composition of the explosive that was being made is not known, but several of the mixtures for which Imperiali had taken out patents were decidedly dangerous.

=*INDURITE= was a smokeless powder patented by C. E. Munroe in 1893. It was made by incorporating guncotton with nitro-benzene to a hard mass. It was used for a time in the American Navy. Samples made in 1891 were still stable apparently in 1914, but some cases of instability occurred and it was given up.

=INGÉLITE= is the same in composition as =ANTIGEL DE SÛRETÉ=.

*Poudre =J.=--A French smokeless powder used for shot-guns and revolvers. Its composition is--

Nitrocotton 83 Ammonium bichromate 14 Potassium bichromate 3 Moisture about 3

It is incorporated with the aid of ether-alcohol and pressed into strips, which are cut into cubes and then converted into grains of irregular shape. The fine siftings are used for revolver and practice ammunition.

=JUDSON POWDER.=--A mild blasting explosive used in America. It is a sort of crude gunpowder coated with nitroglycerine to increase the violence of the explosion. The percentage of nitroglycerine may vary from 5 to 20, but is generally near the lower limit. Judson Powder R.R.P. has the composition--

Nitroglycerine 5 Nitroglycerine 5 Sodium nitrate 64 or Sulphur, coal and resin 35 Sulphur 16 Sodium nitrate 60 Cannel coal 15

The sodium nitrate is mixed with the combustibles and the mixture is heated beyond the melting-point of the sulphur and resin. The slightly porous mass thus formed is then coated with nitroglycerine. The explosive is fired with a priming cartridge of dynamite. The following four grades are made by the Du Pont Co.--

FFF 20 % nitroglycerine FF 15 ” F 10 ” RRP 5 ”

=KANITE A= is an American coal-mine explosive on the Permissible List. It is an ammonium nitrate explosive.