500 



NATURE 



[March 21, 1901 



and show that during the month of January and the first half of 

 February the weather was exceedingly boisterous, and the period 

 was also noteworthy by the great difference of temperature 

 between the eastern and western shores of the Atlantic. For 

 instance, between Fort Logan, in Montana (latitude 47° N.)j with 

 its terribly severe frost of - 61° in the night of February 10, and 

 Liege in Belgium (latitude 48° N.), with its temperature of 

 7o°-5 on the afternoon of the loth, there was a difference of 

 I3i°'S» while over extensive regions of America and western 

 Europe there was a difference of more than 100°. This com- 

 bination of circumstances seemed to indicate the occurrence of 

 some peculiar atmospheric conditions of which the Meteorologi- 

 cal Council considered a permanent record was desirable. 



TnK Proceedings of the American Academy of Arts and Sciences 

 for January contain a description of an ingenious apparatus devised 

 by Mr. F. A. Laws for recording alternating current waves. 

 The system is a modification of the "point-to-point" or 

 " contact " method ; by a mechanical arrangement which auto- 

 matically shifts the position of the contact brushes, the galvano- 

 meter deflection instead of being changed intermittently is 

 made to alter gradually, thus slowly following the wave-form. 

 The reflected spot of light is received on a moving photographic 

 plate on which it imprints a record of the wave-form. The 

 method only gives the average wave-form, but inasmuch as this 

 is obtained in a few minutes, it is a considerable improvement 

 on the older " point-to-point" systems. But now that oscillo- 

 graphs have been developed into thoroughly practical instru- 

 ments by Blondel, Duddell and others, the "point-to-point" 

 method must be regarded, we think, as having had its day. 



Some experiments on the heat evolved when powders are 

 wetted are described by Signor Manfredo Bellati in a recent 

 pamphlet (printed by Carlo Ferrari, of Venice, 1900). It has 

 been suggested as an explanation of the phenomena that the 

 heating is due to the compression produced in the stratum of 

 liquid immediately surrounding the solid, and this explanation 

 has been confirmed by the experiments of Jungk, according to 

 which, when the water is below 4° C. , cooling, instead of heat- 

 ing, takes place, such as would occur in water below the tem- 

 perature of maximum density when subjected to an increase of 

 pressure. This result has been negatived by the experiments of 

 Meissner. The present writer points out, however, that since 

 the effect of pressure is to lower the point of maximum density, 

 it does not necessarily follow that cooling must always occur at 

 temperatures below 4° C, and hence the above hypothesis is 

 not necessarily inconsistent with Meissner's results. In Signor 

 Bellati's experiments dry sand was found to become heated 

 when wetted with water even at a temperature of 0° C. When 

 the sand had been previously moistened, however, the author 

 found that at 0° C. heating occurred when the sand contained 

 more than 2'i or less than i '4 per cent, of water, but that with 

 percentages between these limits cooling sometimes took place 

 instead. The author describes some further experiments con- 

 ducted with the object of testing Canton's and Martini's theory. 



In addition to other communications, the second part of the 

 Bergens Museum Aarbog contains two papers, one by Mr. O. 

 Nordgaard and the second by Mr. E. Jorgensen, dealing with 

 the "plankton" of the North Sea, as well as one by Emily 

 Arnesen, treating of the sponges of the Norwegian coasts. In 

 the fjords of western Norway it is ascertained that the deep 

 plankton fauna is of an Arctic character ; copepods existing in 

 the deep layers, where Atlantic conditions prevail, which attain 

 their maximum development, both as regards size and number, 

 in the Arctic Ocean. We have likewise received the Aars- 

 dereinmg oi the Bergen Museum, in which we notice an excel- 

 lent reproduction of a photograph of a portion of the zoological 

 gallery. 



NO. 1638, VOL. 63] 



The first fasciculus of an important work on the Hydroids, 

 or Hydromedusoe, of the North American seas, now in course of 

 publication by the Smithsonian Institution as Special Bulletin 

 No. 4, has been received. The rich material for the history of 

 this group of zoophytes accumulated in the U.S. National 

 Museum, as one of the results obtained by numerous dredging 

 expeditions of late years, has never hitherto been worked out, 

 and the detailed investigation now being undertaken promises 

 very important additions to our knowledge of the group. The 

 present fasciculus, by Prof. C. C. Nutting, of Iowa University, 

 deals with the Plumulariidse, of which it is doubtful if more 

 than fifty North American species were previously known. The 

 result of the investigation is to show that, in place of Australia, 

 the West Indian area is the richest in plumularian life of any 

 region of the equal size in the world. , j 



We have received the Sitzungsberichte of the Royal Bohemian 

 Society for 1900, which forms a thick volume containing, among 

 other matter, nine articles on zoological and the same number on 

 botanical subjects. Of the former perhaps the most interesting 

 is one by Dr. A. Mrazek, describing the discovery of a small 

 freshwater nemertine worm in a tank in one of the hothouses 

 in the Botanical Garden at Prague. So little is at present 

 known of the freshwater representatives of this group that every 

 new fact is of importance ; but since specimens have been found 

 in regions so far apart as Nicaragua and Turkestan, there can 

 be little doubt that some forms are indigenous to freshwater: The 

 specimen described by Dr. Mrazek is identical with Stichostoma 

 or Tetrastemma, graecense, of which the other known example 

 was taken in a warm-water tank in the Botanical Garden at 

 Gratz ; the species is, therefore, probably introduced. The 

 author adds some general remarks with regard to freshwater 

 faunas. 



The issue of the Revue Scientifique {Revue Rose) of March 9 

 contains a long and interesting article by M. Louis- Adrien 

 Levat on the destruction of birds, especially by means of traps 

 and snares, which he declares to be illicit. After a brief survey 

 of the persecution to which birds were exposed in ancient times, 

 and reference to the fact that taking the hen sitting on her nest 

 is ej:pressly forbidden by the Mosaic code, the author goes on 

 to say that during a single spring a few years ago no less than 

 1500 nests were taken in one French province. This represents 

 a prospective loss of about 6000 birds, which might be expected 

 to consume some 6,000,000 insects among them. He adds the 

 significant observation that in the year i860 one hundred cages 

 filled with insectivorous birds of various kinds were exported from 

 Baden to New South Wales ; and that at the present day it would 

 be almost impossible to send such another cargo, owing to the 

 scarcity of these birds on the continent. And it is not alone 

 the disappearance of bird-life and bird-song from the country 

 districts that is to be deplored. The effects on agriculture, 

 horticulture and the grape industry are simply disastrous. Some 

 birds, it is computed, will consume 200,000 insects per season, 

 and others as many as 600 per day. A single insect-eating 

 species may be the means of saving 3200 grains of wheat and 

 1 150 grapes daily ! In Herault alone the destruction of insecti- 

 vorous birds is- calculated to cost the department 100,000 

 hectolitres of wine annually. And in some districts of France 

 the country is practically desolated by insect ravages owing to 

 bird-slaughter. From the fact that in France so-called sports- 

 men are in the habit of shooting small birds, the situation is 

 much worse than in England. Remedial measures are urgently 

 needed, but the author says he is preaching to deaf ears. 



The Trinidad Bulletin of Miscellaneous Information states 

 that a recent analysis made by Prof. Carmody, Government 

 Analyst, confirms the previous work of Francis as to the 

 presence of prussic acid in sweet cassava, the proportion found 



