It is by thus adding to the sources of Indian wealth that England will best discharge the immense responsibility she has incurred by the conquest of India, so far as the material interests of that vast empire are concerned. Thus too will she leave behind her by far the most durable monument of the benefits conferred by her rule. The canals and other works of the Moguls were in ruins before the English occupied the country; but the melons which the Emperor Baber, the founder of the Mogul dynasty, introduced into India, and which caused him to shed tears while thinking of his far-off mountain-home, still flourish round Delhi and Agra. Centuries after the Ganges canal has become a ruin, and the great Vehar reservoir a dry valley, the people of India will probably have cause to bless the healing effects of the fever-dispelling chinchona-trees, which will still be found on their southern mountains. The introduction of the chinchona-plant into India was surrounded by difficulties from which all other undertakings of a similar nature have been free. When tea was introduced into the Himalayan districts, it had been a cultivated plant in China for many ages, and experienced Chinese cultivators came with it. But the chinchona had never been cultivated; since the discovery of its value in 1638 it had remained a wild forest tree; all information concerning it was solely derived from the observations of European travellers who had penetrated into the virgin forests; and the only guidance for cultivators in India is to be found in the reports of these travellers, and in the experience slowly acquired by careful and intelligent trials.[115] Great as these difficulties were, they were probably exceeded by the perils and risks of every description which must be encountered in collecting plants and seeds in South America, and conveying them in safety to India. But the vast importance of the introduction of these plants into our Indian empire, and the inestimable benefits which would thus be conferred on the millions who inhabit the fever-haunted plains and jungles, were commensurate with the difficulties of the undertaking. The subject had occupied the attention of the Indian Government from time to time, ever since Dr. Royle in 1839 advocated the introduction of quinine-yielding trees into India, in his work on Himalayan Botany; but it was not until twenty years afterwards, in 1859, that any adequate steps were taken to effect this most desirable end, and to bring an antidote within the reach of the fever-stricken people of India, while adding a new source of wealth to the resources of that great dependency.