They are all apparently traveling directly away from the large star close by them, in straight lines which may, of course, be the projections of closed curves; but their rates of travel are so different as to involve certain progressive separation.  Obviously, the order and method of such movements as are just beginning to develop to our apprehension among the Pleiades will not prove easy to divine.—­A.M.  Clerke, in Nature.

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DEEP SEA DREDGINGS:  EXAMINATION OF SEA BOTTOMS.

By THOMAS T.P.  BRUCE WARREN.

I believe Prof.  Ehrenberg was one of the first to examine, microscopically, deep sea dredgings, some of which were undertaken for the Atlantic cable expedition, 1857.

I propose to deal with the bottoms brought up from tropical waters of the Atlantic, a few years ago, during certain telegraph cable operations.  These soundings were made for survey purposes, and not for any biological or chemical investigations.  Still I think that this imperfect record may be a useful contribution to chemical science, bearing especially on marine operations.

Although there is little to be added to the chemistry of this subject, still I think there are few chemists who could successfully make an analysis of a deep sea “bottom” without some sacrifice of time and patience, to say nothing of the risk of wasting a valuable specimen.

The muds, clays, oozes, etc., from deep water are so very fine that they pass readily through the best kinds of filters, and it is necessary to wash out all traces of sea water as a preliminary.  The specimen must be repeatedly washed by decantation, until the washings are perfectly free from chlorine, when the whole may be thrown onto a filter merely to drain.  The turbid water which passes through is allowed to stand so that the suspended matter may settle, and after decanting the clear supernatant water, the residuum is again thrown on to the filter.

The washing and getting ready for the drying oven will, in some cases, require days to carry out, if we wish to avoid losing anything.

So far the proceeding is exactly the same, except draining on a filter, which would be adopted for preparing for the microscope.  On no account should the opportunity be missed of mounting several slides permanently for microscopic examination.  Drawings or photographic enlargements will render us independent of direct microscopic appeal, which is not at all times convenient.

The substance, if drained and allowed to dry on the filter, will adhere most tenaciously to it, so that it is better to complete the drying in a porcelain or platinum capsule, either by swilling the filter with a jet of water or by carefully removing with a spatula.  The most strenuous care must be used not to contaminate the specimen with loose fibers from the filter.