In the Senate at Washington, on the 18th ult., some discussion took place upon this subject, and an amendment was proposed, which provided that no persons but those who were actually necessary to the taking and registering of measurements, c, should accompany the expedition. -Mr. Houston, in a humorous speech, expressed his sentiments upon the subject of scientific men accompanying such expeditions. He said: " The catching of a single bug of rare quality immortalizes a scientific gentleman, and a lizard or a horned frog confers double immortality"— from which he deduced that these gentlemen have their own aggrandizement more at heart than the purposes of the expedition. This may ha very true; but when a new country is explored, it is necessary that astronomer! should visit it, that the world may be informed of the astral peculiarities; its geology and natural history should be described; and more than all, its physical geography is important. To discover these facts, and to arrange them intelligently, scientific men must visit the place ; and it is a very false economy on the part of any government not to give them all the aid they require. In many climates insects eat up a crop before its maturity, and so cause a famine ; and if by a scientific man this insect can be discovered and killed, " the catching of a single bug " may not only immortalize the catcher, but also benefit a whole community. We say, support scientific explorations, for there are people in the world who see more than pictures in the books published by Uncle Sam, and who regard them with more interest than giving them to amuse children.