The first patent for waterproofing seems to have been granted in 1791. A Charles Macintosh invented the garment named after him in 1823.
Very little of the commercial rubber is obtained from the common india-rubber Fig (Ficus elasticus) which we commonly grow indoors. This is one of those species of the Fig family which are generally found growing on the branches or trunks of other trees, though their own roots crawl down the trunk of the support to the ground. Once these roots have reached the ground, they take firm hold and grow so large and thick that they may be able to hold up the Fig tree even if the original support decays and crumbles away.
The gutta-percha which we use comes chiefly from Singapore, which is a sort of world's market for rubber. There are a great many different varieties and substitutes of this substance, but the best kinds come from Malaysia, Singapore, Sumatra, Java, and Borneo. The uses of gutta-percha and of vulcanite, which is manufactured from it, are very varied. Thus, it is employed for the soles of boots, door-handles, pipes, ear-trumpets, buckets, submarine cables, etc. It is indestructible in sea-water, and does not conduct electricity.
A very extraordinary exception to the general rule that latex is highly poisonous, is found in the famous Cow Tree of Venezuela. This tall tree (it is often 100 feet high) is found in large forests near Cariaco, on the coast of that country. Its milk is said to closely resemble ordinary milk in taste, and to be perfectly wholesome and nutritious, but it is rather sticky. This tree was responsible for all sorts of curious and extraordinary legends in the sixteenth and seventeenth centuries.
CHAPTER XXV
ON CLIMBING PLANTS
Robin-run-the-Hedge—Bramble bushes—Climbing roses—Spiny, wiry stems of smilax—The weak young stem of a liane—The way in which stems revolve—The hop and its little harpoons—A climbing palm—Rapidity of turners—The effect of American life on them—Living bridges—Rope bridges in India—The common stitchwort—Tendrils—Their behaviour when stroked or tickled—Their sensibility—Their grasping power—The quickness with which they curve and their sense of weight—Charles Darwin—Reasonableness of plants—Corkscrew spirals—The pads of the Virginian Creeper—The ivy—Does it do harm?—Embracing roots—Tree ivy.
THERE are many plants which depend upon and cling to other more sturdy kinds, and which would be quite unable to live upon the earth at all if they had not developed the most beautiful methods of doing so.
In autumn, as soon as the leaves of the Hawthorn have fallen off, one is sure to find upon the hedges the common Robin-run-the-Hedge (Goosegrass, Cleavers, or Sticky Willie, for it is known by all these nicknames as well as by its proper name, Galium aparine).
Its stem is exceedingly weak, but it will be found sometimes to be six or seven feet long. It does not support itself, but is resting amongst and entangled in the outer twigs of the hedge in such a manner that it cannot be blown away by the wind or indeed picked out without its being broken. The young stems grow upright and are vigorous at first, but soon they cannot bear their own weight, and fall back upon a branch of the hedge. There are small curved little roughnesses along the stem and on the under side of the leaves of the Galium; these hitch on to the twig. Up to this point then the stem is supported, and the young part above grows until it also gets a lodgment, and so it goes on until it sometimes reaches right over the top of the hedge.