'May 15, 19 19] 



NATURE 



219 



SOCIETIES AND ACADEMIES. 

 London. 

 Royal Microscopical Society, April 16. — Mr. J. E. 

 Barnard, president, in the chair. — J. Strachan : The 

 chemistry of dendritic growths in paper. The forma- 

 tion of these interesting and curious growths was for- 

 merly attributed to the oxidation of a particle of 

 bronze or brass included in the sheet of paper during 

 manufacture. Later investigations have proved, how- 

 ever, that the chemical reactions producing these 

 .growths are more complex. The particle of bronze 

 is attacked by chemical residues in the paper, chief 

 among which is sulphate of aluminium, with the 

 formation of soluble sulphate of copper. The latter 

 creeps along the fibres in solution. The sulphate of 

 copper is then reduced to insoluble black sulphide 

 of copper, which constitutes the majority of recent 

 dendrites in paper. This sulphide is further oxidised 

 again to sulphate, and so by alternate oxidation and 

 reduction insoluble copper compounds may be 

 deposited along the fibres. The final action in old 

 dendrites is oxidation, resulting in the formation of 

 basic copper sulphate. The chemistry of these growths 

 is important in that they indicate, by secondary re- 

 actions, the nature of chemical actions taking place in 

 he deterioration of paper during ageing, in which the 

 ellulose is attacked by chemical residues from various 

 sources. A new micro-chemical test for the detection 

 of copper sulphide consists in the application to the 

 dendrite of a solution containing the double cyanide of 

 potassium and cadmium. The black copper sulphide 

 dissolves, but is exactly replaced by a brilliant yellow 

 pseudomprph of cadmium sulphide, forming a yellow 

 dendrite. The principle of this mode of testing by 

 replacement appears to be capable of further applica- 

 tions in micro-chemical manipulation. — Dr. E. Penard : 

 Folliculina boltoni, S. Kent. In spite of recent state- 

 ments to the contrary, the genus Folliculina is un- 

 doubtedly represented in fresh-water, and the vermi- 

 form' bodies (described as Lagynus ocellatus by Daday) 

 represent, as already suspected by several authors, 

 though contradicted by others, a free-swimming form 

 produced by a metamorphosis of the whole individual. 

 Zoological Society, April 29. — Prof. E. W. MacBride, 

 vice-president, in the chair. — Dr. W. T. Caiman : 

 Marine boring animals. Attention was directed to 

 the economic importance of the scientific investigation 

 of these forms of marine animals in relation to the 

 serious damage caused by them to the timbers of 

 ■wooden ships and to piers, and to the masonry of 

 breakwaters and similar constructions. — G. Jenni8»n : 

 A diimpanz^e in the open air in England. Attention 

 was directed to the fact that the animal had lived 

 in a healthy and vigorous condition for a period of 

 some eight years in the private grounds of its owner, 

 Dr. John K. Butter, of Cannock, Staffordshire. 



Linnean Society, May i. — Sir David Prain, president, 

 in the chair. — J. Smith : Forms assumed by the pappus 

 in Compositae. As all the facts adduced in support of 

 the phyllome theory can be explained by assuming 

 that the pappus in certain cases is partly a develop- 

 ment of the hairs which were inserted on the now 

 aborted but once free calyx-segments, the evidence in 

 favour of the trichome or emergence nature of the 

 organ admits of no other conclusion than that which 

 takes the pappus to be "hairs, free or fixed, derived in 

 their evolution from the hairs of the achene, or some- 

 times also from the hairs of the now aborted calyx- 

 limb. — J. M. F. Drummond : The flora of a small area 

 in Palestine. The author gave the route covered by 

 the 52nd Division (of which he was a member) 

 between El Arish and the neighbourhood of Jaffa. 

 Collections were made at various points along this 



NO. 2585, VOL. 103] 



route, and the area of .\rsuf, fifteen miles north of 

 'Jaffa, was specially described, with the topography 

 and climate. The edaphic plant-formations were dealt 

 with, especially two — the "Calcareous Knoll" flora 

 and the " Cistus Moor" ; the former is of the nature of 

 garigue, and contains many geophytes and annuils, 

 with many minor xerophilous characters, but few 

 extreme types, with only one switch-plant and no 

 succuients. Cistus Moor has a dosed carpet of vegeta- 

 tion, few geophytes or annuals. Cistineae and a tus- 

 sock-grass predominate ; possibly akin to the Cistus- 

 maqui of Spain. Garigue and Steppe prevail in 

 western Palestine ; Maqui was not seen at all by the 

 author. Possibly this state of affairs is partly due 

 to man's interference. 



Dublin. 

 Royal Irish Academy, April 28.— Dr. R. F. Scharff, 

 vice-president, in the chair. — N. Colgan : The occur- 

 rence of tropical drift seeds on the Irish Atlantic 

 coasts. Seeds or fruits of no fewer than eight tropical 

 species have been found, cast up from time to 

 time, on the Irish coasts. All the species are native 

 or naturalised in the West Indies, and all have highly 

 buoyant seeds, capable, as Dr. Guppy has shown,' of 

 floating for twelve months and upwards. The Irish 

 stations for these drift seeds range from Donegal 

 to Kerry, and the records of their occurrence are 

 spread over a couple of centuries. It has been sug- 

 gested that the passage of these ocean waifs is effected 

 bv human agency. The author decides in favour of 

 the idea that the tropical drift seeds cast up on the 

 Irish Atlantic beaches are wafted thither from their 

 West Indian home bv natural agencies. An acconnt 

 of the seeds and of 'the plants which produce them 

 is given .-^. P. Mantagn : A study in regeneration in 

 wheat {T riti cum vulgar e). .\ number of simultaneous 

 sowings of wheat were made, and shoots were am- 

 putated at various stages in • their development.^ The 

 various theories of regeneration were reviewed in the 

 light of the facts disclosed in Triticum, and two hypo- 

 theses were put forward, viz. (i) the regeneration 

 observed may be traced to the disturbance in the 

 normal absorption-transpiration-equilibrium, following 

 the removal of the shoots bv amputation, and (2) the 

 regeneration observed may be regarded as due to the 

 disturbance, consequent on the injury involved in the 

 amputation, of the normal enzyme-balance. ^ Such a 

 disturbance leads to hydrolysis of glucoside within the 

 plant, the cydic element ' functioning as the direct 

 causal activator of the regeneratintf growths, while 

 the carbohydrate split-product is utilised to build up 

 the regenerating tissue. 



BOOKS RECEIVED. 



Outlines of Theoretical Chemistry. By Dr. F. H. 

 ' Getman. Second edition. Pp. xiii+ssg. (New York : 

 i J. Wiley and Sons, Inc. ; London : Chapman and 

 Hall, Ltd.) 165. 6d. net. 



Applied Optics. The Computation of Optical 

 Svstems, being the " Handbuch der Angewandten 

 Optik" of Dr. A. Steinheil and Dr. E. Voit, trans- 

 lated and edited bv J. W. French. Vol. ii. Pp. vi + 

 207+plates V. (London : Blackie and Son, Ltd.) 

 I2S. 6d. net 



Reports of the Progress of Applied Chemistry. 

 Issued by the Societv of Chemical Industry. Vol. iii. 

 Pp. 495- (London:' Society of Chemical Industry.) 

 los. 6d. 



How and What to Read. Suggestions towards a 

 Home Library. By R. B. Buckley. Pp. 176. 

 (London : Willi&ms and Norgate.) 25. 6d. net. 



Meteorologia Aeronautica. By Prof. G. Crestani. 

 Pp. XV+315. (Milano : U. Hoepli.) 8.50 lire. 



