THE question of the supply of india-rubber to meet the present enormous demands caused by the progress of electrical science, and the rapid development of the application of the substance for cycle and carriage tyres, is one that has been much discussed of late, and continues to increase in interest. For some time past it has been well known that the trees which supply the best rubber known in commerce, namely, Para rubber, have been more and more difficult to get at, in consequence of the collectors having to proceed further into the forests in search of the trees (Hevea brasiliensis) which yield the valuable juice. But though greater distances have to be traversed in order to collect the rubber, there seems but little fear of the absolute failure of the rubber supply generally, or of this one particular kind. Though the quality of this rubber is of a very superior nature, we are fortunately not dependent alone upon it for the supplies of our markets, for from the East and West Coasts, as well as from Central Africa, and also from India and the Far East, we obtain very respectable quantities; indeed, the resources from tropical Africa in this respect have of late so much increased, that they promise to compensate for any loss of the American supplies, and the experiences of the past year or so, when a new source of rubber has been discovered at Lagos, is even more reassuring as to the future supplies, for other plants may yet be found capable of assisting in furnishing a substance that will probably, in the future, be in still greater demand than it is even now. So that it has become necessary for every one interested in this peculiar industry to take every precaution to prevent waste of material, both in the processes of collecting the milky juices and in the preservation of the plants yielding them.