Page:Popular Science Monthly Volume 8.djvu/528

512 in its action, but a painless means of killing the criminal.

sums up as follows the results of numerous experiments made in order to test the efficacy of the sulpho-carbonate of potassium, in destroying the grape-phylloxera: In the first place, the phylloxera is destroyed wherever the solution of the salt or its vapor penetrates. Secondly, the vine itself suffers no injury. Occasionally, a very few living phylloxeræ are seen after treatment; but these come from other neighboring vines which have not been treated with the sulpho-carbonate, or have been hatched from eggs which have in some way been protected from the action of the salt.

naturalist attached to the Challenger expedition, died at sea on the passage from Hawaii to Tahiti, on September 13, 1875, aged twenty-eight years. He was a native of Schleswig-Holstein, and was educated at the Universities of Göttingen and Bonn. He early showed a very strong taste for natural history, and when only a boy published papers on the habits of European birds. After leaving Bonn he was appointed Privat-Docent in Zoölogy in the Munich University. He went to Italy in 1868, making zoölogical observations at Spezzia, and in 1872 visited the Faröe Islands. He then joined the Challenger expedition. He was a man of unusual acquirements and culture.

biennial prize of 20,000 francs has been awarded by the Institute of France to M. Paul Bert, for his discoveries on the effects of oxygen in the act of respiration. Some of the principal results of Bert's researches have been stated in the pages of the According to the eminent physiologist, Claude Bernard, Bert's discoveries are "the most astounding that have been made since the discovery of oxygen by Priestley."

Royal Society of London has awarded to Mr. Crookes a "Royal Medal," for his various chemical and physical researches, more especially for his discovery of thallium, his investigation of its compounds, and determination of its atomic weight, and for his discovery of the repulsion referable to radiation.

interesting experiment made by G. Planté, and described by him to the Paris Academy of Sciences, may possibly explain the spiral form of many of the nebulae. The two copper electrodes of a battery of 15 elements being immersed in water containing one-tenth of sulphuric acid, the pole of a magnet is brought near to the end of the positive electrode. Immediately the cloud of metallic particles, borne away from this electrode by the current, assumes in the liquid a gyratory, spiral motion, resembling in appearance a spiral nebula.

will be gratifying to our readers to learn that the preliminary operations of the expedition sent under the auspices of the Hydrographic Office, United States Navy, to determine telegraphically the relative longitudes of points in the West Indies, have been so far successful. Captain Green, U. S. N., assisted by the officers of the United States ship Gettysburg, and by Mr. Rock, civil assistant, has so arranged his programme that the two temporary observatories at Havana and Key West are in the same circuit, and that the signals made at either station are recorded directly, without the intervention of the observer at the second station, on his chronograph. It is to be presumed that an important element of uncertainty is thus eliminated. All the arrangements for the work are in good order, and Captain Green acknowledges the most cordial assistance from the officials of the Government and of the cable companies.

production of gum in fruit-trees, M. Prillieux regards as a disease, which he names gummosis. The alimentary substances in the interior tissues, instead of promoting the plant's growth, are diverted to the production of gum, and a portion of them accumulates about gummy centres, which seem to act as centres of irritation. The production of gum at the expense of nutritive matter has no limit short of the complete exhaustion of the plant. The best remedy is scarification. To cure the disease, the materials appropriated to forming gum must be restored to their normal destination. Hence, a more powerful attraction for them must be introduced than that of the gummy centres. Now, the wounds of the bark necessitate the production of new tissues, and, under this strong excitation, the reserve matters are employed in the formation of new cells, and cease to be attracted in the wrong direction.

instrument for the rapid examination of oils and textures by means of electricity has been invented by Prof. Palmieri. The instrument will—1. Show the quality of olive-oil; 2. Distinguish olive-oil from seed-oil; 3. Indicate whether olive-oil has been mixed with seed-oil; 4. Show the quality of seed-oils; 5. It will indicate the presence of cotton-fibres in silk and woolen textures.

is stated by Dr. Malherbe that sewing-silk is sometimes impregnated with acetate of lead, and that seamstresses are frequently poisoned by introducing such thread into the mouth.