“In June, 1859, very soon after the formation of my garden, the leaf-cutting ants came down upon it, and at once commenced denuding the young bananas, orange, and mango trees of their leaves. I followed up the paths of the invading hosts to their nest, which was about one hundred yards distant, close to the edge of the forest. The nest was not a very large one, the low mound of earth covering it being about four yards in diameter. At first I tried to stop the holes up; but fresh ones were immediately opened out. I then dug down below the mound and laid bare the chambers beneath, filled with ant-food and young ants in every stage of growth. But I soon found that the underground ramifications extended so far and to so great a depth, whilst the ants were continually at work making fresh excavations, that it would be an immense task to eradicate them by such means; and notwithstanding all the digging I had done the first day, I found them as busily at work as ever at my garden, which they were rapidly defoliating. At this stage our medical officer, Dr. J. H. Simpson, came to my assistance, and suggested the pouring carbolic acid, mixed with water, down their burrows. The suggestion proved a most valuable one. We had a quantity of common brown carbolic acid, about a pint of which I mixed with four buckets of water, and, after stirring it well about, poured it down their burrows. I could hear it rumbling down to the lowest depths of the formicarium, four or five feet from the surface. The effect was all that I could have wished; the marauding parties were at once drawn off from my garden to meet the new danger at home. The whole formicarium was disorganized. Big fellows came stalking up from the cavernous regions below, only to descend again in the utmost perplexity.