Messrs Fairbairn and Wells, Manchester, have lately much improved their screw forging machine. By this method of making screws, it is claimed that much greater tenacity, ductility, and durability are obtained in the finished product; for the fibres of iron, instead of being cut through, are pressed and bent round to the shape of the thread. In short, the machine rolls out the screws, instead of cutting them out. We have lately seen photographs of some of these screws which have been partially eaten away with acid, for the purpose of showing the fibrous nature of the metal. It is curious to note how the fibre is bent in and out as it follows the direction of the thread on the screw. This method of manufacture is said to present advantages apart from better quality. The screws can be more quickly produced at a less cost, and there is a great saving of material, for nothing is cut away to waste. The results of a curious but very important test as to the accuracy with which chemists, druggists, and others make up prescriptions committed to their care, has recently been presented to one of the London vestries. Fifty prescriptions were sent out to ordinary druggists, to co-operative stores, to ‘doctors’ shops,’ and to certain traders styling themselves drug Companies. The mixtures made were afterwards analysed, to find out how nearly they agreed with the prescriptions they represented; but in order to give a liberal margin for error, it was resolved not to put a black mark against any one, if the chief constituent were within ten per cent. of the right amount. Notwithstanding this margin, no fewer than seventeen out of the fifty mixtures were incorrectly dispensed. In one case the principal drug was less by eighty-five per cent. than the amount ordered, while in another it was fifty-seven per cent. in excess. The chemists and druggists came out best in this strange competition, as only six per cent. of their prescriptions had to be called in question. Next came the co-operative stores with twenty per cent. of error; then the ‘doctors’ shops’ with fifty per cent.; and lastly the drug Companies, who are credited, or rather discredited, with seventy-five per cent. of errors. OCCASIONAL NOTES. THE ROOSEN METHOD OF PRESERVING FISH.