512 



THE POPULAR SCIENCE MONTHLY. 



in its action, but a painless means of killing 

 the criminal. 



Dumas 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-phyl- 

 loxera : 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 phylloxeras 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. 



Dr. Rudolf von Willemoes-Suhm, nat- 

 uralist attached to the Challenger expedition, 

 died at sea on the passage from Hawaii to 

 Tahiti, on September 13, 18*75, aged twenty- 

 eight years. He was a native of Schleswig- 

 Holstein, and was educated at the Univer- 

 sities of Gottingen and Bonn. He early 

 showed a very strong taste for natural his- 

 tory, and when only a boy published pa- 

 pers on the habits of European birds. 

 After leaving Bonn he was appointed Pri- 

 vat-Doceut in Zoology in the Munich Uni- 

 versity. He went to Italy in 1868, making 

 zoological observations at Spezzia, and in 

 1872 visited the Faroe Islands. He then 

 joined the Challenger expedition. He was 

 a man of unusual acquirements and culture. 



The 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 re- 

 searches have been stated in the pages of 

 the Monthly. According to the eminent 

 physiologist, Claude Bernard, Bert's discov- 

 eries are " the most astounding that have 

 been made since the discovery of oxygen 

 by Priestley." 



The Koyal Society of London has 

 awarded to Mr. Crookes a " Royal Medal," 

 for his various chemical and physical re- 

 searches, more especially for his discovery 

 of thallium, his investigation of its com- 

 pounds, and determination of its atomic 

 weight, and for his discovery of the repul- 

 sion referable to radiation. 



An interesting experiment made by G. 

 Plante, 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 con- 

 taining 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. 



It will be gratifying to our readers to 

 learn that the preUminary 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 ob- 

 servatories at Havana and Key West are in 

 the same circuit, and that the signals made 

 at either station are recorded directly, with- 

 out 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 offi- 

 cials of the Government and of the cable 

 companies. 



The production of gum in fruit-trees, 

 M. Prillieux regards as a disease, which he 

 nAmQsgummosis. The alimentary substances 

 in the interior tissues, instead of pro- 

 moting 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 form- 

 ing gum must be restored to their normal 

 destination. Hence, a more powerful at- 

 traction for them must be introduced than 

 that of the gummy centres. Now, the 

 woimds of the bark necessitate the pro- 

 duction 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 direc- 

 tion. 



An 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 wliether 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. 



It is stated by Dr. Malherbethat sewing- 

 silk is sometimes impregnated with acetate 

 of lead, and that seamstresses are frequently 

 poisoned by introducing such thread into 

 the mouth. 



