39' 



SCIENTIFIC NEWS. 



[April 27, iS 



tifique and Naturforschcr) prolonged freezing decidedly 

 reduces the number of bacteria in water. Before freezing 

 a sample of water contained (per cubic centimeter ?) 

 6,300 individuals of Bacillus prodigiosus. After four 

 days' freezing the number was only 2,970 ; after 37 days 

 22, and after 51 days none. Bacteria can resist a long 

 continuous cold much better than rapid changes from low 

 to high temperatures and inversely. The bacillus of 

 typhus fever has an exceptional power of resisting cold. 



Heating Effect of Electric Currents. — A contempo- 

 rary says : " M. Cailletet, a French electrician, has con- 

 ducted a series of experiments which show that the 

 heating effect of an electric current, as shown in a piece 

 of platinum wire, is proportionately diminished as the 

 pressure of the air around such wire is increased. The 

 converse has long been established. M. Cailletet has 

 shown that a current which would fuse a wire under 

 ordinary pressure will scarcely raise it to redness when 

 the pressure is sufficiently great. This shows how 

 essential free convection and radiation are to the in- 

 candescence of the filaments of glow lamps." 



The Outline of Continents. — Mr. A. Agassiz, in his 

 work on American " Thalassography," contends that the 

 real outline of the continents is the " hundred fathom 

 line," which often, though not always, corresponds to the 

 present coast line. Beyond this line the descent to the 

 depths of the ocean is very steep. The space between 

 the coast-line and the margin of the hundred-fathom line, 

 is spoken of as the continental shelf. It is covered with 

 the debris brought down by the rivers from the land. 

 Professor Agassiz seeks to prove that the great con- 

 tinental areas and the great ocean basins must always 

 have maintained their present relative positions. 



Preserving the Natural Colour of Flowers. — The 

 Pltar. Jour, draws attention to R. Hegler's method of 

 preserving the natural colour of flowers, which consists 

 in dusting salicylic acid on the plants as they lie in the 

 press, and removing it again with a brush when the 

 flowers are dry. Red colours in particular are well 

 preserved by this agent. Another method of applying 

 the same preservative is to use a solution of one part of 

 salicylic acid in fourteen of alcohol by means of blotting- 

 paper or cotton-wool soaked in it, and placed above and 

 below the flowers. Powdered boracic acid yields nearly 

 as good results. Dr. Schonland {Gardener's Chron.) 

 recommends as an improvement in the method of using 

 salicylic acid for preserving the colours, that in the 

 case of delicate flowers they might be placed loosely 

 between sheets of vegetable parchment before immersion 

 in the liquid, so as to preserve their natural form. 



Forestry and Locusts in Cyprus. — From the recently 

 issued report of Her Majesty's Acting High Commis- 

 sioner at Cyprus for 1SS6-7 we regret to notice that tree 

 planting has not been carried out to the extent that is 

 desirable from want of funds. About 3,000 trees have 

 been planted round Nicosia during the year, and about 

 2,6co given away to villagers who are glad to get them. 

 One hundred and sixty eucalyptus have been given to the 

 Commissioner of Nicosia to plant round the Mudirate at 

 Morphon. Up to the date of the report they were doing 

 well, but as no funds were available for protecting them 



againstthe straying village animals the Forestry Inspector 

 is afraid they may be eaten off. The Ouillaria sap- 

 onaria, sandal, sweet chestnut, and cork oak, mentioned 

 in the report of 18S4-5 as having been planted, have all 

 failed, mainly from the excessive heat. Though there is 

 a marked diminution in the illegal cutting of trees still 

 the Inspector complains seriously of the damage done by 

 goats to the young trees. Little progress in forestry wiU 

 be made in Cyprus until young plantations are effec- 

 tuallj' fenced against the inroads of the goats. The results 

 of the Locust Campaign of 1886-7 are reported as on the 

 whole satisfactory. The Government Engineer states 

 that during the past four years little or no damage has 

 been done by the common locust. The results would 

 have been much more favourable if the people generally 

 took more interest in locust destruction and worked 

 earnestly for their extermination. 



The Past Winter in North Italy. — Dr. G. Hellmann, 

 the well-known meteorologist of Berlin, has published 

 some data respecting the climatic conditions of Upper 

 Italy during the past winter which possess general in- 

 terest. Within recent years the winter has only once 

 been so severe in Italy as that from which we are just 

 emerging — namely, in December, 1879, ^^^ January, 

 1880. The Riviera then suffered even more than this 

 winter, while for Upper Italy the conditions were about 

 the same. According to Dr. Hellmann, the thermometer 

 fell in Genoa and Porto Maurizio (124 miles east of San 

 Remo) ten times below freezing point from the end of 

 December, 1887, to the beginning of February, 1888, and 

 twice as many ground frosts and hoar frosts were ob- 

 served. The lowest air temperatures in the Riviera 

 were, according to the situation of the place of observa- 

 tion, between — 3 deg. and — 6 deg. C. (26 deg. and 21: 

 deg. Fahr.). About 25 miles north of Genoa, in the 

 longitudinal axis of the Po valley, on the contrary, the 

 thermometer fell repeatedly to — 15 deg. C. (5 deg. 

 Fahr.) and even — 17 deg. C. (1-4 deg. Fahr.). From 

 December 26 to January 23, consequently for nearly 

 thirty days, the temperature remained at Alessandria 

 uninterruptedly below zero. During the period between 

 December 21 to January 31, the following minima of 

 temperature were registered: — Alessandria, — 15 '6 deg. 

 C. (about 4 deg. Fahr.) ; Pavia, — 12-7 deg. C. (8 deg. 

 Fahr.); Piacenza, — 17 deg. C. (1-4 deg, Fahr.); Cre- 

 mona, — 13'5 deg. C. (7'5 deg. Fahr.); Mantua, — ii'8 

 deg. C. (11 deg. Fahr.); Ferrara, — 13-6 deg. C. (7'5 

 deg. Fahr.) ; Rovigo, — 15 deg. C. (5 deg. Fahr.) ; Milan, 

 —8 deg. C. (17-6 deg. Fahr.); Padua, —8-9 deg. C. 

 (15 deg. Fahr.); Turin, — 10 deg. C. (14 deg. Fahr.); 

 Venice, — 6-2 deg. C. (20-5 deg. Fahr.); Parma, — 137 

 deg. C. (7'5 deg. Fahr.); Ravenna, — 12'6 deg. C. (8 

 deg. Fahr.). " From January r to 10, 1888," says Dr. 

 Hellmann, " the temperature on the plateau of Cuneo 

 was only about 8 deg. C. (about 15 deg. Fahr.) higher 

 than in the valley of the Tanaro, near Alessandria, 

 which lies 1,476 ft. lower, and the well-watered lowland 

 bay of which, as well as the Po valley near Piacenza, 

 may be called the Italian Siberia." It may be finally 

 remarked that, according to the data furnished by Dr. 

 Hellmann, during the period above mentioned, the 

 following lowest temperatures were registered in various 

 parts of Italy : — Florence, — 6-5 deg. C. (about 20 deg. 

 Fahr.); Rome, — 3-4 deg. C. (25 deg. Fahr.); Naples,— 

 17 deg. C. (29 deg. Fahr.) ; Cozenza, — 3'8 deg. C. (24 

 deg. Fahr.) ; Palermo, ^o'2 deg. C. (31 deg. Fahr.). 



