356 



NATURE 



SJ\Jarch 4, 1S75 



form into nymphre ; ten to fourteen days later the young beetles 

 appear; thus one summer can see three or four generations, 

 of which the last one passes the winter in the ground. The 

 insect does not confine its devastations to the potato only, but 

 has also been found to attack the youn;j sliojts and leaves of 

 Cirsiifii Itimwlnliim, Amaranthus i-etivjhxus, Lisymbrium offici- 

 nal^; Polygonum hydri'pifcr, Solaituiii iiii^nim, ChcuopiHlium 

 liybridum and album, and even of Ilyosiyamits niger. This 

 variety of plants shows that the insect has great powers of adapt- 

 ing itself to its food, and to this it must be ascribed that it can 

 only with the greatest difficulty be got rid of. The home of the 

 insect was in the Rocky Mountains ; with the'^westward progress 

 of agriculture the cultivation of the' potato approached the birth- 

 pl.ice of the insect, and it transferred its dwelling to the potato 

 fields, which ol course were welcome food; thus in a short time 

 it became a general plague. In 1S59 it began its eastward pro- 

 gress, and has now reached the coast of the Atlantic ; whether 

 it will cross this ocean and begin its devast-itions in Ireland 

 remains to be seen ; much maj-, however, be done to prevent its 

 appearance in Europe. The means used for its destruc- 

 tion are various ;' the most successful one has been the so-called 

 Schweinfuit green (arseno-acetate of copper). This is mixed 

 with flour and wa'.er, and the plants are sprinkled with 

 the mixture. Although highly piisonous to animal life, the 

 Schweinfurt green doej not poison the soil, as it is perfectly 

 insoluble in water, and the dest'uclion'of the noxious insect is 

 almcst complete. Dr. Kalender finally draws the attention of 

 agriculturists to another potato enemy, the Brystopha solandla, a 

 minute mo'h which has made its appearance in Algeiia ; its 

 larvx completely destroy the potatoes themselves, so that they 

 become unfit even for pigs' food. The Journal de la SocU'li Cm- 

 Irak d' HorlicKlliire en Fiance warns seriously against the impor- 

 tation of Algerian potatoes. 



Don Pedro, Emperor of Brazil, has been elected a corre- 

 sponding member of the French Academy of Sciences for the 

 tection of Geography and Navigation. Don Pedro is the third 

 emperor who has been a member of the Academy. Tire first 

 was Peter the Great, elected a geographical correspondent. In 

 that capacity he sent a map of the Caspian Sea, which is still 

 kept in the records of the'lAcademy. The second imperial 

 Academician was Napoleon I., -who was a member of the section 

 of Mechanics, but resigned after his abdication at Fontainebleau. 

 Napoleon III. tried to get appointed a member, but was not 

 successful. 



The Academy of Sciences lost one of its most celebrated 

 home correspondents in the same week as it did Lyell — a foreign 

 correspondent. On the ist inst., M. Fremy, the President, 

 announced the demise of M. Seguin the elder, at the age of 

 eighty-nine. M. Seguin was educated by his elder brother, and 

 was himself a most daring engineer. He was the contractor of 

 the Lyons and Saint Etienne Railway in 1S25, a railway which 

 was worked by horses and ropes for years. He is believed in 

 France to have invented suspension bridges. He maintained at 

 his own expense, during twenty years, the publication of Cosmos, 

 a scientific periodical in which he expounded his own ideas on 

 the doctrine of the conservation of force, of which he was a keen 

 and active supporter. 



An exploring expedition will shoitly leave Marseilles to make 

 researches into the depths and animal organisations of the 

 Mediterranean. Soundings and dredgings similar to those made 

 by the Challenger will be made by a steamer specially provided 

 with microscopes, photographic apparatus, and means for pre- 

 serving new or rare specimens of marine zoology. The expedi- 

 tion is entirely due to private enterprise. 



The International Conference on the Metrical System met 

 at Paris on Monday under the presidency of the Due Decazes, 



who explained that the object of the Conference was the conclu- 

 sion of a Convention between States adopting or permitting the 

 use of the metre as the basis of measurement. The Conference 

 has transferred the solution of the questions to be decided to a 

 Commission composed of delegates of the various Governments. 

 M. Dumas, the Permanent Secretary to the Academy of Sciences, 

 has been appointed President of this Commission, Mr. Chisholm 

 being the English delegate. 



M. Leverrier has established in the Paris Observatory a 

 registry, where all tie scientific facts collected from the several 

 political papers may be cut and labelled. Such a register was 

 kept during the last year of Arago's superintendence, but has 

 been discontinuedfor years. 



On the 23rd of February the Italian Geographical Society 

 discussed the advisability of sending an Italian expedition viA 

 the Red Sea to the sources of the Nile. The members were 

 unanimous in favour of the scheme, and a programme will be 

 issued shortly. 



The picturesque city of Caub, in Nassau, near Barhirach, will 

 very shortly, it is said, be crushed and destroyed by the disinte- 

 gration of the mountain on which Guterfeld Castle was built in 

 mtdi.-cval times. The rocks which threaten Caub are not less 

 than 600 feet in height. Two rows of houses have been de- 

 serted, as no human power can prevent the catastrophe. 



Several continental papers note the fall of ponderous rocks 

 caused by the recent frosty weather. Snch occurrences as that 

 referred to in our last number as having occurred at Moen are 

 very frequent on the banks of the Seine. La A'aliire publishes 

 a sketch taken at Sainte Adresse, near Havre, illustrating the 

 progressive levelling of these lofty cliffs partly by the action of 

 the waves, and partly by weathering. 



On Feb. 18 Dr. Gerhard Rohlfs delivered alectureat Cologne 

 on the last part of his journey from Tr poli to thecoast of Guinea, 

 which is of particular scientific interest. He treated in detail 

 the stale of civilisation of the Empire of Bornu (situated near 

 Lake Tsad) and its capital, Kuka, and it appears that the negro 

 tribes that inhabit those parts are highly civilised, in fact much 

 more so than most other tribes in Northern Africa. From Kuka 

 Dr. Rohlfs went to Mandara, which is situated south of Bornu, 

 and then entered the districts of the Pullo (or Fullo) tribes ; -he 

 found the inhabitants to be of light yellow, almost white com- 

 plexion, and surpassing even Europeans with regard to beauty of 

 form and growth. Dr. Rohlfs then descended the Tshadda 

 River, down to where this joins the Niger, and was hospitably 

 received by the English colonists at Lokoja ; from here he 

 visited a negro country in a western direction, then passed the 

 Kong Mountains, and success'ully traced his way through the 

 thick tropical forests to the coast, which he reached near 

 Lagos. 



The first annual meeting of the Scientific Club was held on 

 Thursday, the l8th inst., Capt. Marshall Hall, F.G.S., in the 

 chair, when a report was presented showing the great progress 

 which has been made since] the foundation of the club on the 

 19th of March last. 



The additions to the Zoological Society's Gardens during the 

 past week include two Wild Boars (Siis serofa), European, pre- 

 sented by Mr. Sebastlan.Anderson ; a Grey Ichneumon (Herpestes 

 gnsens) from India, presented by Miss R. Barter ; a Common 

 Raccoon [Procyon lo/o>-) from North America, presented by Miss 

 Julia Jackson ; a Hening Gull (La: us argenlaius), European, 

 presented by Miss Jessie Bovill ; two Petz's Conures (Ci'««?-«.f 

 fdzii) from Peru, presented by Miss Hornby ; two Sarus Cranes 

 {Cms anli^ivie) from North India; a Mandarin Duck (Aix 

 galcricnlata) from China, received in exchange; three Common 

 Pezifowl (Pavo crisiata) from India, deposited. 



