2. The pipes must as a rule be of iron, though lead may be used where they are uncovered and not exposed to risk of injury. Rubber connexions may only be used for portable apparatus, and attached to a terminal on the metal pipes provided with a cock, and be fastened at both ends so that they will not slip off the nozzles. In regard to (_d_), residues, it is enacted that special open or well-ventilated pits must be provided for their reception when the apparatus exceeds 300 litres per hour productive capacity. With smaller apparatus they may be discharged into cesspools if sufficiently diluted. The ITALIAN GOVERNMENT regulations in regard to acetylene plant are divided into eight sections. The first of these relates to the production and use of liquid and compressed acetylene. The production and use of liquid acetylene is prohibited except under the provisions of the laws relating to explosives. Neat acetylene must not be compressed to more than l-1/2 atmospheres except that an absolute pressure of 10 atmospheres is allowed when the gas is dissolved in acetone or otherwise rendered free from risk. Mixtures of acetylene with air or oxygen are forbidden, irrespective of the pressure or proportions. Mixtures of acetylene with hydrocarbons, carbonic oxide, hydrogen and inert gases are permitted provided the proportion of acetylene does not exceed 50 per cent. nor the absolute pressure 10 atmospheres. The second section relates to acetylene installations, which are classified in four groups, viz., (_a_) fixed or portable apparatus supplying not more than thirty burners consuming 20 litres per hour; (_b_) private installations supplying between 30 and 200 such burners; (_c_) public or works installations supplying between 30 and 200 such burners; (_d_) installations supplying more than 200 such burners. The installations must comply with the following general conditions: 1. No part of the generator when working at its utmost capacity should attain a temperature of more than 100° C. 2. The carbide must be completely decomposed in the apparatus so that no acetylene can be evolved from the residue. The residues must be diluted with water before being discharged into drains or cesspools, and sludge storage-pits must be in the open. 3. The apparatus must preclude the escape of lime into the gas and water connexions. 4. Glass parts must be adequately protected. 5. Rubber connexions between the generator, gasholder, and main are absolutely prohibited with installations supplying more than 30 burners. 6. Cocks must be provided for cutting off the main and connexions from the generator and gasholder. 7. Each burner must have an independent tap. 8. Generators of groups (_b_), (_c_), and (_d_) must be constructed so that no after-generation of acetylene can take place automatically and that any surplus gas would in any case be carried out of the generator house by a vent-pipe.