20 cm. long, straight form, with side electrodes and 50 mm. long fine capillary in the middle. Filled with Oxygen, Neon, Helium, Air Nitrogen, Argon. Ammonia Vapours, Alcohal Vapuours, Carbon Dioxide, Hydrogen, Lodine Vapour, Sulpher Water Vapurs.

20 cm. long, straight from, with side electrodes and 50mm long fine capillary in the middle. Filled with Acetylene, varpours Carbonic Acid, Carbon Dioxide, Chlorine Hydrogen Sulphide, Nitrogen, Sulphurous Acid, Xenon, Methyl Alcohal.