PROGRESS OF CHEMISTRY.--FORTY NEW SUBSTANCES.--"During the decade ending with 1886 over forty discoveries of new elementary substances were announced, while the entire number previously known was less than seventy. No less than nine were detected by Crookes last year. The list is likely to be lengthened quite as materially in the current twelvemonth, as A. Pringle already claims to have found six new elements in some silurian rocks in Scotland. Five of these are said to be metals, and the other is a substance resembling selenium, which the discoverer calls hesperisium. One metal is like iron, but does not give some of its reactions; another resembles lead, is quite fusible and volatile, and forms yellow and green salts; another, named erebodium, is black; the fourth is a light-gray powder, and the last is dark in color." ASTRONOMY.--"The absolute dimensions of a globular star cluster have been studied by Mr. J. E. Gore of the Liverpool Astronomical Society. These clusters consist of thousands of minute stars, possibly moving about a common center of gravity. One of the most remarkable of these objects is 13 Messier, which Proctor thinks is about equal to a first magnitude star. Yet Herschel estimated that it is made up of fourteen thousand stars. The average diameter of each of these components must be forty-five thousand two hundred and ninety-eight miles, and each star in this wonderful group may be separated from the next by a distance of nine thousand million miles." "According to the computations of M. Hermite, a French astronomer, the total number of stars visible to the naked eye of an observer of average visual power does not exceed 6000. The northern hemisphere contains 2478, and the southern hemisphere contains 3307 stars. In order to see this number of stars, the night must be moonless, the sky cloudless, and the atmosphere pure. The power of the naked eye is here stayed. By the aid of an opera glass 20,000 can be seen, and with a small telescope 150,000, while the most powerful telescopes will reveal more than 100,000,000 stars." "M. Ligner, an Austrian meteorologist, claims to have ascertained after careful investigation that the moon has an influence on a magnetized needle, varying with its phases and its declination. The phenomenon is said to be more prominently noticeable when the moon is near the earth, and to be very marked when she is passing from the full to her first or second quarter. The disturbances are found to be in their maximum when the moon is in the plane of the equator, and greater during the southern than it is during the northern declination." GEOLOGY ILLUSTRATED.--I have often thought that when coal mines are exhausted and land is too valuable to be devoted to raising timber, it may become necessary to draw on the subterranean heat of the earth. This idea is already verified in Hungary.