April lo, 1890] 



NATURE 



547 



change in this. The blood was examined by measuring the 

 position of absorption bands of haemoglobin with a given thick- 

 ness o( layer, and estimating their darkness. No change in the 

 (juality of haemoglobin was detected, but the quantity, in some 

 individual?, judging by changes in the width and darkness of 

 the bands, was les«ened towards the end of winter. Holmgren 

 suggested, as an experitiientum cruets with regard to the question 

 of a subjective or objective cause, that someone should exclude 

 himself from sunlight a month longer than the others : and to 

 this infliction the engineer Andree submitted. When he left his 

 prison, his skin had a greyish-yellow tint. The conclusion 

 arrived at is that the change of skin is due to an anxmic- 

 chlorolic condition, possibly that of incipient scurvy. 



We have received Tylar's "Photographic Calendar" for the 

 year 1890. It comprises, among other advantages, practical hints 

 selected from the best contributors, and various reproductions of 

 severalof the pictures that gained prizes in the competition 

 held last year. There is also an extended list of the author's 

 specialities, as well as those of other dealers ; and throughout 

 there is a variety of useful information handy for reference. 

 The prize list is more varied and comprehensive than that given 

 last year. 



The "Photographers' Diary and Desk-book" for the year 

 1890, which is issued by the proprietors of the Camera, is a very 

 handy and useful volume. Developing and other formulae are 

 printed in large type, capable of being read in the dim light of 

 the dark room. A series of dark-room procedures has been 

 added, including the work of developing the negative, silver 

 printing and toning, platinotype printing (cold, hot, and sepia 

 processes), Blanchard's platinum black process, and bromide 

 printing. A selection of the most important and useful of the 

 recent improvements in photographic apparatus is given, with 

 several illustrations, preceded by some particulars of the objects 

 of the Photographic Convention of Great Britain, with a list 

 of its officers. The diary portion, interleaved throughout with 

 blotting-paper, gives ample space for the daily record of 

 photographic work. 



The Royal Horticultural Society has issued the first part of 

 vol. i. of its Journal. This part includes reports of the 

 Vegetable Conference held at Chiswick on September 24, 25, 

 and 26, 1889, and of the Chrysanthemum Conference held at 

 Chiswick on November 5 and 6, 1889. 



The Transactions of the Congres Colonial and the Congres 

 d'Hygiene et de Demographic, held in Paris last summer, have 

 been issued. The Transactions of the latter Congress cover over 

 1200 octavo pages, and include many really useful papers. 



Michel Troja was one of the first surgeons who experi- 

 mented (1775) on the regeneration of bone. His book, "De 

 Ossium Kegeneratione," has just been published, for the first 

 time, in French. 



The last Annual Report of the Dutch Colonies in the East 

 Indies contains references to several subjects of scientific 

 interest. The military surveys were carried out on the west 

 coast of Sumatra and in Dutch Borneo. In the former a large 

 area was mapped on a scale of I ; 20,000, and in Borneo a 

 flying survey of I : 200,000 was made over a considerable district. 

 Triangulation and cartographical work were continued in 

 Sumatra ; various maps were finished in Batavia ; and the parts 

 of the great map of Netherlands India, including the Residencies 

 of Madura and Pasuruan, were put in hand at the Hague. The 

 members of the Hydrographic Department were busy on the 

 coasts of Java and Madura ; an astronomical station was estab" 

 lished on the Sunda Islands ; and the study of the languages of 

 the archipelago was continued by gentlemen appointed for the 

 purpose— Balin, Javanese, Old Javanese, Macassar, Bugin, &c. 

 There are 182 meteorological stations in working order, 100 in 



Java and Madura, 34 in Sumatra, 6 in Billiton and Banka, 9 irr 

 Borneo, 17 in Celebes, 2 in Bali, and the remainder at other 

 points in the archipelago. Of scientific expeditions of various- 

 kinds a long list is given. These include geological investiga- 

 tions in Sumatra and Flores, botanical on Key Islands, ethno- 

 logical in the Balta region of Sumatra, ethnological, botanical,, 

 and zoological, on the east coast of Borneo. An arrangement 

 has been made, by which in each year one student from home 

 will be able to spend some months in the famovs Buitenzorg. 

 Botanical Gardens. 



Another paper by Drs. Curtius ^and Jay upon hydrazine, 

 NjHj, describing a new .ind very simple method of obtaining 

 this recently isolated base from the ammonia addition compound 



/-H 

 pfaldehyde, CH.,.Cv OH , is communicated to the latest num- 



^NH.^ 

 ber of the Berichte. The first step consists in acting with 

 sodium nitrite upon a cold slightly acidified aqueous solution of 

 aldehyde-ammonia, by which a nitroso-compound of the com-i 



/" . 

 position CgHjjOa • C a is formed. The reaction probably 



^N.NO 

 completes itself on the lines of the following equation — 



.H /H 



SCHg.C^OH -fNO.OH^CsHjiOo.C^ +2H2O + 



\NHo "■ ^N— NO 



2NH3. About 300 grams of aldehyde ammonia are dissolved in 

 a little ice-cold water, and neutralized with cold dilute sulphuric 

 acid. About 40 c.c, more of the dilute acid are then added, 

 and afterwards a concentrated solution of 70 grams sodium 

 nitrite in iced water. The liquid at once becomes turbid owing 

 to separation of minute yellow globules of the nitroso-compound, 

 termed nitroso-paraldimine, on account of its derivation from 

 paraldehyde, the triple polymer of common aldehyde. This 

 nitroso-paraldimine is a lemon-yellow liquid possessing an in- 

 tense camphor-like odour. Its molecular weight has been 

 determined by Ilofmann's density method, and found to cor- 

 respond with the formula above quoted. It decomposes at its 

 boiling-point, but may be readily distilled in steam or in vacuo 

 without suffering change. The imine itself, corresponding to 

 the nitroso-compound, has also been isolated. The hydro- 



chloride, C3Hn02 . C^ , is obtamed when moist 



^NH.HCl 

 hydrochloric acid gas is passed through an ethereal solu- 

 tion of nitroso-paraldimine, in the form of a mass of white 

 needles. From this hydrochloride the free base, paraidimine, 



CrHi,0., .CV , may be obtained by treating its ether 



^-NH 

 solution with silver oxide. Paraldimine is a clear colourless, 

 liquid of a sharp odour resembling that of paraldehyde. It 

 solidifies to while crystals jn a freezing mixture. It boils- 

 almost without change at 140° C, but polymerizes to a white 

 solid on standing in a sealed tube for some weeks. Water 

 or alcohol decompose it into paraldehyde and ammonia. Its 

 hydrochloride, which is readily formed from the base with 

 great evolution of heat by leading dry hydrochloric acid 

 gas over the pure liquid, may be converted into the nitroso- 

 compound by treating with a strong solution of sodium nitrite. 

 The nitroso-compound itself, on reduction with zinc dust and 

 dilute sulphuric acid, at once yields hydrazine sulphate, 

 N„H4 . H0SO4. The course of the reaction is better seert 

 when the gentler reducing mixture, zinc dust and glacial 

 acetic acid, is allowed to act upon an ethereal solution of 

 nitroso paraldimine. An amide termed amidoparaldimine,. 



/\\ 

 CsHi.O., . Ca , is then first formed, and may be 



^N.NHa 



