June 22, 1893 



NATURE 



'83 



"Xkb. Johns Hopkins University Circular, No. io6, is chiefly 

 taken up with morphological notes from the biological labora- 

 tory of the Johns Hopkins University. Prof. William K. 

 Brooks contributes two important notes on the Salpa embryo, 

 and Mr. M. M. Metcalf describes an apparently new species 

 of Octacnemus, a deep-sea, Salpa-like tunicate. A memoir 

 on the genus Salpa, by Prof. Brooks, will shortly be published. 

 It will contain about three hundred and fifty quarto pages, with 

 sixty coloured plates. The memoir is based for the most part 

 upon material collected by the United States Fish Commission. 



"Electric Light Installations and the Management of 

 Accumulators," by Sir David Salomons, Bart., has reached a 

 seventh edition. This edition has been, to a large extent, re- 

 written, and is now published by Messrs. Whittaker and Co. 

 under the title "The Management of Accumulators," as the 

 first volume of a series dealing with electric light installations. 



Two further papers upon azoimide, N3H, are contributed to 

 the current number^of the Berichte by Prof. Curtius. In the 

 first, a brief but important communication, it is shown that 



NHa, 

 azoimide may be prepared directly from hydrazine, | by the 



NHj 

 action of nitrous acid. 



NH, N\ 



I '+ ON -OH = 1! NH + 2H„0. 

 NH,^ N/ 



It is only necessary to lead the red oxides of nitrogen evolved 

 from a mixture of nitric acid and arsenious oxide into an ice-cold 

 aqueous solution of hydrazine hydrate until a vigorous evolution 

 of gas, due to decomposition, commences. A dilute aqueous 

 solution of azoimide is thus obtained with whichSmost of the re- 

 actions of the substance can be 'performed. It is preferable, 

 however, to first condense the red gaseous mixture by means of 

 ice and salt, and to pour the blue liquid, a few drops at a time, 

 into the cold hydrazine solution until the evolution of gas begins. 

 The experiment is unattended by any danger, and is therefore 

 admirably adapted for lecture purposes. Now that hydrazine 

 is so well known and so readily obtained, the sulphate being 

 already a commercial article, this mode of obtaining azoimide 

 will doubtless be adopted by most lecturers for class demon- 

 stration, especially as the reaction is one of such fundamental 

 theoretical importance. 



In the second communication Prof. Curtius describes an in- 

 interesting new organic synthesis of azoimide. When hydrazine 

 hydrate is caused to act upon a salt of diazobenzene, a fugitive 

 compound is obtained of the constitution indicated by the 

 formula CeHjN : N.NH.NHj. This compound might be 

 expected to decompose in two ways, breaking up either at the 

 double linkage or at the single linkage between the NH and 

 NH2 groups. According to the former mode there would be a 

 migration of two hydrogen atoms from two different nitrogen 

 atoms to a third nitrogen atom with production of aniline and 

 azoimide, C„H.,N : N.NH.NH, = CuH^NHj -(- N,,H. Accord- 

 ing to the latter mode of decomposition one hydrogen atom 

 would migrate and form ammonia with the last amido group, 

 leaving diazobenzene imide, thus: CjHjN : N.NH.NH,, = 

 CbHjNj + NH3. As a matter of fact both decompositions 

 occur, the latter somewhat predominating. It is quite easy, 

 however, to isolate 10 per cent, of the theoretical yield of azoi- 

 mide. Equi molecular saturated aqueous solutions of hydrazine 

 sulphate and diazobenzene sulphate are mixed and poured into 

 a 3 per cent, solution of sodium hydrate. A turbidity is at once 

 produced, which eventually coalesces into an oil. This is ex- 

 tracted with ether and ammonia, expelled from the aqueous 

 solution by boiling. The liquid, which contains the sodium salt 

 of azoimide, is then rendered slightly acid with sulphuric acid 

 NO. 1234, VOL. 48] 



and distilled, when azomide passes over along with the steam. 

 The ethereal extract contains the aniline together with diazo- 

 benzene imide produced according to the second mode of 

 decomposition. 



Notes from the Marine Biological Station, Plymouth. — The 

 arrival of Midsummer renders desirable a summary of the re- 

 cords which have been made in this paragraph during the past 

 six months of the breeding seasons of marine animals at Ply- 

 mouth. The records have approximately indicated the com- 

 mencement of the breeding seasons ; but it should be premised 

 that in the great majority of instances the period of reproduc- 

 tion is prolonged throughout the summer months, and is already 

 at an end only in a few isolated cases. The following have 

 been recorded : — The Gymnoblastic Hydroids Tubularia bellis, 

 Clava multicornis and cornea, Eudendrium ramosum and 

 capillare, together with the Anthomedusse Rathkea octopunctata 

 (now over), Bougainvillea ramosa, Amphinema Titania, Sarsia 

 prolifera and tiibulosa, Podocorytic carnea and Corymorpha 

 nutans ; the Calyptoblastic Hydroids Halecium (halecimim and 

 Beanii), Plumularia sctacea a.Ddpinnata, Antennularia ramosa 

 and antennina, Sertularella (Gayi), Sertularia argent ea and 

 pumila, Hydrallmania {falcata), Gonothyraa Loveni, together 

 with the Leptomedusae Obelia lucifera, Clytia Johnstoni, Irene 

 pellucida, Phialidium variabile, Laodice cruciata, Thaumantias 

 octona, Forhesii, and Thompsoni ; the Ctenophore Hormiphora 

 plumosa ; the Actinians Cereanthus (Arachnactis,- — now over), 

 Halcampa chrysanthellum, Ceretis pedunctilatus, Bunodes verru- 

 cosa, Urticina felina and Actinia equina ; the Nemertines 



I Cephalothrix linearis and bioculata, Amphiforus dissimnlans. 

 Riches (= piilcher of previous record, March 30), Nemertes 



j Neesii, and Linens obscurus ; the Polychteta Phyllodoce ma- 



\ culata, Cirratulus cirratus, Polydora {/lava ?), Sabellaria 

 spinuloia, and various Terebellidce and Serpulidiv. The Poly- 

 noid larva; which swarmed in the Sound in the early Spring 



' are no longer to be obtained. The Mollusca, Crustacea, 

 Echinodermata and Chordata will be summarised next week. 



The additions to the Zoological Society's Gardens during the 

 past week include three Peba Armadillos ( Tatusia peba, cj (J 9 ) 

 from South America, presented by Mr. Woodbine Paiish ; two 

 Brazilian Cariamas (Cariama cristata) from Paraguay, presented 

 by Mr. A. E. Macalister Hadwen ; five Spotted-billed Ducks 

 [Anas pircilorhyneha, 4 (5 1 9 ) from India, presented by Sir E. 

 C. Buck, C.M.Z. S. ; a Guillemot {Lomvia troile) British, pre- 

 sented by Mr. T. A. Cotton, F.Z.S. ; two Chiff-chaffs {Phyl- 

 loscopus rufus), two Yellow Wagtails (Motacillaflava) British, 

 presented by Miss McGill : a Naked-necked Iguana {Iguana 

 delicatissima) from the Caicas Islands, West Indies, presented 

 by Lady Blake; a Lobed Chameleon {Chamccleon parvilobus) 

 from Barberton, Transvaal, presented by Dr. Percy Rendall ; 

 two Capybaras (Hydrochttrus capybara) from South America, 

 purchased ; an English Wild Bull [Bos taurus, var.), a Burrhel 

 Wild Sheep {Ovis burrhel, 9 ), a Derbian Wallaby [Halmaturus 



■ derbianus, 9 ) born in the Gardens. 



OUR ASTRONOMICAL COLUMN. 



A New Variable « Cygnus. — In photographing the region 

 of a Cygni, Dr. Max Wolf (Astronomischen Nachrichten, No. 

 •3168), on examining the plates, has found a new variable, its 

 position for 1893 'O being R.A. 2oh. 47 •2m., Decl. 4- 45° 49'. 

 The star, he says, is very easy to find, lying as it does in the 

 south right-angle corner of a.right-argled triangle, the stars in the 

 other corners being B.D. stars + 45 3300 and -f45°'3302. 



The brightness, as obtained from the plates, gave the following 

 numbers : — 



