"2. The customer shall have the right to refuse to take carbide yielding in the sizes mentioned above less than 4.2 cubic foot, per lb., and it shall lie, in case of refusal and as from the date of the result, of the analysis being made known to either party, at the risk and expense of the seller.
"3. The carbide shall not contain higher figures of impurities than shall from time to time be fixed by the Association.
"4. No guarantee shall be given for lots of less than 3 cwt., or for carbide crushed to smaller than the above sizes.
"5. In case of dispute as to quality, either the buyer or the seller shall have the right to have one unopened drum per ton of carbide, or part of a ton, sent for examination to one of the analysts appointed by the Association, and the result of the examination shall be held to apply to the whole of the consignment to which the drum belonged. "6. A latitude of 5 per cent, shall be allowed for analysis; consequently differences of 5 per cent. above or below the yields mentioned in 1 and 2 shall not be taken into consideration.
"7. Should the yield of gas be less than 4.8 cubic feet less 5 per cent., the carriage of the carbide to and from the place of analysis and the cost of the analysis shall be paid for by the seller. Should the yield be more than 4.8 cubic feet less 5 per cent., the carriage and costs of analysis shall be borne by the buyer, who, in addition, shall pay an increase of price for the carbide proportionate to the gas yield above 4.8 cubic feet plus 5 per cent.
"8. Carbide of 1 inch mesh and above shall not contain more than 5 per cent. of dust, such dust to be defined as carbide capable of passing through a mesh of one-sixteenth of an inch.
"9. The seller shall not be responsible for deterioration of quality caused by railway carriage in the United Kingdom, unless he has sold including carriage to the destination indicated by the buyer.
"10. Carbide destined for export shall, in case the buyer desires to have it tested, be sampled at the port of shipment, and the guarantee shall cease after shipment.
"11. The analyst shall take a sample of not less than 1 lb. each from the top, centre, and bottom of the drum. The carbide shall be carefully broken up into small pieces, due care being taken to avoid exposure to the air as much as possible, carefully screened and tested for gas yield by decomposing it in water, previously thoroughly saturated by exposure to acetylene for a period of not less than 48 hours.
"12. Carbide which, when properly decomposed, yields acetylene containing from all phosphorus compounds therein more than .05 per cent. by volume of phosphoretted hydrogen, may be refused by the buyer, and any carbide found to contain more than this figure, with a latitude of .01 per cent. for the analysis, shall lie at the risk and expense of the seller in the manner described in paragraph 2.