An air that contained ten thousandths of CO_{2}, or even five, would be almost as deleterious, in my opinion, as one of two per cent.  It is of no account, then, to know the proportions intermediate to these round numbers.  Yet it is possible, if the case requires it, to obtain an indication between two consecutive figures of the scale by means of another bulb whose capacity is only half that of the preceding.  Thus, two injections of the large bulb, followed by one of the small, or two and a half injections, correspond to a richness of 8 thousandths of CO_{2}; and 51/2 to 3.6 thousandths.  This half-bulb serves likewise for another purpose.  From the moment that the large bulb makes the lime-water turbid with an air containing two per cent. of CO_{2}, it is clear that the small one can cause the same turbidity only with air twice richer in CO_{2}, i.e., of four per cent.

This apparatus, although it makes no pretensions to extreme accuracy, is capable of giving valuable information.  The table that accompanies it is arranged for a temperature of 17 deg. and a pressure of 740 mm.  But different meteorological conditions do not materially alter the results.  Thus, with 10 deg. less it would require thirty-one injections instead of thirty, and CO_{2} would be 0.64 per 1,000 instead of 0.66; and with 10 deg. more, thirty injections instead of thirty one.

The apparatus is contained in a box that likewise holds a bottle of lime-water sufficient for a dozen analyses, the table of proportions of CO_{2}, and the apparatus for cleaning the tubes.  The entire affair is small enough to be carried in the pocket.—­J.  Arnould, in Science et Nature.

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[NATURE.]

THE VOYAGE OF THE VETTOR PISANI.

Knowing how much Nature is read by all the naturalists of the world, I send these few lines, which I hope will be of some interest.

The Italian R.N. corvette Vettor Pisani left Italy in April, 1882, for a voyage round the world with the ordinary commission of a man-of-war.  The Minister of Marine, wishing to obtain scientific results, gave orders to form, when possible, a marine zoological collection, and to carry on surveying, deep-sea soundings, and abyssal thermometrical measurements.  The officers of the ship received their different scientific charges, and Prof.  Dohrn, director of the Zoological Station at Naples, gave to the writer necessary instructions for collecting and preserving sea animals.

At the end of 1882 the Vettor Pisani visited the Straits of Magellan, the Patagonian Channels, and Chonos and Chiloe islands; we surveyed the Darwin Channel, and following Dr. Cuningham’s work (who visited these places on board H.M.S.  Nassau), we made a numerous collection of sea animals by dredging and fishing along the coasts.

While fishing for a big shark in the Gulf of Panama during the stay of our ship in Taboga Island, one day in February, with a dead clam, we saw several great sharks some miles from our anchorage.  In a short time several boats with natives went to sea, accompanied by two of the Vettor Pisani’s boats.