March 13, 1884] 



NA TURE 



469 



The author cite-; several methods by means of which aa appa- 

 rent neutrality is shown to be the result of internal reaction, and 

 that in all cases, even in the most permanent magnet, there is a 

 portion of it reversed to its apparent polarity. 



The author shows the importance of the knowledge of this 

 fact in the construction of electro-magnets, whenever we desire 

 to have the maximum of effect whilst under the iofluence of a 

 current with a minimum of remaining magnetism when the 

 influence ceases. 



This is shown by experiments upon bars of similar length but 

 of different thickness, solid bars having far greater effect than 

 tubular ones. Experiments were made on electro-deposited iron 

 of varying thickness, showing the remarkable retentive power of 

 extremely thin coatings of soft iron. 



The result is given of a series of researches not yet com- 

 pleted (the details of which will be published in a future paper) 

 upon the saturating point of soft iron and steel. The author 

 has found that the atmosphere as well as all gaseous matter 

 has precisely a similar curve of magnetic rise from neutrality to 

 its magnetic saturation, and that bismuth as well as all so- 

 called diamagnelic bodies obey the same law of saturation. 

 Consequently he assumes that all matter is strongly magnetic, 

 the widest limit yet found, from bismuth to soft Swedish iron, 

 being only forty times greater for the iron. 



An explanation is given of the well-known disappearance of 

 magnetism at yellow red heat, in which the author a sumes, 

 from observed effects of violent mechanical vibrations, that this 

 disappearance is due to a violent molecular oscillation destroy- 

 ing its symmetrical arrangement of polarity. 



The author concludes by saying, " Whatever theory we adopt 

 as an explanation of evident nragnetism, it will be found that 

 neutrality occurring after the cessation of an external inducing 

 force upon a bar of iron or steel is the result of symmetrically 

 opposed polar forces, producing apparent waves of opposite 

 polarity, or reactions between the exterior and interior of a bar 

 of iron." 



Linnean Society, March 6. — Sir J. Lubbock, Bart., presi- 

 dent, in the chair. — Dr. A. B. Shepherd and Mr. Jas. Dallas 

 were elected Fellows, and Mr. W. Hodgson an Associate of the 

 Society. — The President announced the receipt of an intimation 

 from the Foreign Office (through the Science and Art Depart- 

 ment) of an International Ornithological Congress to be held in 

 Vienna in the beginning of April. — Mr. J. Britten exhibited 

 specimens of Lithospermum purpurea cceruleum, illustrating 

 points in the life history of the plant as described by Mr. J. W. 

 White in the Journal of Botany. — Mr. F. O. Bower drew 

 attention to a figure published in the Gardener's Chronicle repre- 

 senting a case of proliferation of the so-called " double needle " 

 of Sciadopitys verticillata. He alluded to the various views as 

 to the morphological value of the "double needle," and con- 

 cluded that the one first propounded by Prof. A. Dickson, after- 

 wards discussed adversely by Von Mohl, but favourably by 

 Goebel, appears most in accordance with the history of its 

 development. — Dr. M. Masters showed and made remarks on an 

 example of bud variation of Pinus silvcstris. — There was exhi- 

 bited for Mr. T. E. Gunn a stuffed specimen of a male variety of 

 the common moorhen [Gadinula chloropus), shot near Norwich 

 last spring. — Mr. A. W. Bennett drew attention to specimens 

 under the m'croscope of species of Ptilota and Callilhamnion 

 which demonstrated the continuity of the protoplasm. — Prof. 

 Cobbold gave a verbal account of a communication from Dr. P. 

 Mansonof Hong Kong, in which the author furnishes fresh evidence 

 as to the role of the mosquito considered as the intermediary host ■ >i 

 Filaria sanguinis-hominis . Dr. Manson has verified his previous 

 observations in the most complete manner, and he now recognises 

 and describes six well-marked stages of the Filarije whilst they 

 are dwelling within the body of the insect. In the discussion 

 following. Dr. T. R. Lewis confirmed Manson's statements in 

 inany particulars. — The Secretary read an abstract of a paper on 

 the Indian species of Cyperus, with remarks on some others that 

 specially illustrate the subdivisions of the genus. The author 

 divides this memoir into three sections : (l) a descriptive account 

 of each part of a Cyperus, viz. the culm, inflorescence, &c. , com- 

 paring these successively in all the Indian species ; (2) contains a 

 discussion of some difficult species and disputed genera ; (3) is a 

 systematic arrangement with descriptions of the Indian species, 

 with short citations of some non-Indian species that more parti- 

 cularly illustrate the subdivisions and groups. — Prof. St. G. 

 Mivart read a paper on the relations between instinct and other 

 vital processes. In this he contended that instinct cannot be , 



divided by a very hard and fast line from such vital processes as 

 reflex action, processes of repair after injuries, and the process 

 of development of the individual ; and that these latter were 

 more readily explained as activities especially instinctive, than 

 that instinct could be explained by reflex action or by lapsed 

 intelligence. The vital processes referred to were also shown to 

 have an important bearing on the question of the origin of 

 species. — Then followed a paper, notes on Afghanistan alga;, 

 by Dr. J. Schaarschmidt, founded on material derived from 

 Surgeon-Major Aitchison's collection of plants made during 

 the Afghanistan Expedition in 18S0. 



Zoological Society, March 4.— E. W. H. Holdsworth, 

 F.Z.S., in the chair. — Mr. Howard Saunders, F.Z.S., exhibited 

 and made remarks on specimens of two Gulls (Xema sabini and 

 Larus philadtlphia) in the breeding-plumage, both killed in 

 Scotland. Mr. Saunders also made some observations upon the 

 specimen of Larus atricilla in the British Museum, said to be 

 the one killed by Montagu at Winchelsea, and came to the 

 conclusion that the bird in question was not Montagu's speci- 

 men. Mr. Saunders likewise exhibited a specimen of Puffinus 

 griseus killed off the Yorkshire coast. — A letter was read from 

 Dr. Ch. W. Liitken, Foreign Member, calling attention to a 

 specimen of an Echidna in the Zoological Museum of Copen- 

 hagen, which seemed to be different from the ordinary Tachy- 

 glossus aculeatus, and which Dr. Liitken was of opinion might 

 possibly be referable to the lately-described T. lawesi of 

 New Guinea. — Mr. J. E. Harling, F.Z.S., exhibited and made 

 observations on some antlers of roe deer from Dorsetshire and 

 Scotland. — Mr. W. R. Ogilvie Grant read a paper on the fishes 

 of the genera Sicydium and Lentipes (belonging to the family 

 Gobiidae), in which an attempt was made to arrange the species 

 oS. Sicydium into smaller groups, the members of which were 

 found to be allied together by convenient and distinctive cha- 

 racters. Five new species of Sicydium were described. — A 

 communication was read from Mr. F. Moore, F.Z.S., on some 

 new Asiatic Diurnal Lepidoptera, chiefly from specimens in the 

 Calcutta Museum. — A communication was read from the Count 

 T. Salvadori, C.M.Z.S., eontaining some critical remarks on an 

 African Duck, Anas capcnsis, Gmelin. 



Chemical Society, March 6. — Dr. W. H. Perkin, presi- 

 dent, in the chair. — It was announced that a ballot for the elec- 

 tion of Fellows would take place at the next meeting (March 20), 

 — The following papers were read : — Studies on sulphonic acids, 

 No. i. ; on the hydrolysis of sulphonic acids, and on the recovery 

 of benzenes from their sulphonic acids, by Drs. H. E. Armstrong 

 and A. K. Miller. By passing steam through a solution of the 

 sulphonic acids or the sulponates in their own weight of sulphuric 

 acid, the authors find that all the benzenes can be recovered. 

 No decomposition of any of the benzenes tried takes place, and 

 an almost theoretical yield is obtained. The method has been 

 of great value in separating the hydrocarbons obtained from 

 camphor. — On a relation between the critical [temperature of 

 bodies and their thermal expansions as liquids, by T. E. Thorpe 

 and A. W. Riicker. By conibining the simple expression 

 recently published by Mendeleeff for the expansion of liquids 

 with some of the conclusions arrived at by Van der Waals, the 

 authors arrive at the result that the density of a liquid is very 

 nearly proportional to the number obtained by subtracting its 

 absolute temperature from twice its absolute critical temperature. 

 — Remarks on the densities of members of homologous series, 

 by Dr. W. H. Perkin. The author has plotted curves in the 

 usual way, taking the number of carbon atoms as abscis' je, and 

 a scale of numbers embracing those of the densities at lo" C. as 

 ordinates. The bodies examined consisted chiefly of very care- 

 fully purified acids and ethers of the fatty series. It is obvious 

 from the curves that the densities of the homologous acids and 

 ethers follow a regular law. — Note on some experiments made 

 at the Munster Agricultural School to determine the value of 

 ens lage as a milk- and butter-producing food. Cows were fed 

 on ensilage for a week and on mixed food for a week, and the 

 author has analysed the milk and weighed the butter produced. 

 The results in the two experiments are almost identical, so that 

 ensilage is not inferior to ordinary food. — Note on the behaviour 

 of the nitrogen of coal during destructive distillation and a com- 

 parison of the amount of nitrogen left in cokes of various origin, 

 by Watson Smith. — On a hitherto unnoticed constituent of 

 tobacco, by T. J. Savery. The author, having noticed in 

 tobacco a substance which strongly reduced Fehling's solution, 

 investigated the subject, and separated a body closely resembling 



