396 



NA TURE 



[February 22, 1894 



twelve monthly volumes to be entitled "The Country, Month 

 by Month." Mr. Lock wood Kipling has supplied a design for 

 the cover. The first number will appear on March i, and will 

 be descriptive of that month. 



A NEW work is announced by Mr. Leland, bearing upon his 

 favourite subject — practical education. The manual deals with 

 elementary metal work, including bent iron, repousse, cut 

 melal, and easy silver work. It is written primarily for manual 

 training classes in elementary and preparatory schools, but will 

 probably be found interesting to any one who has a mechanical 

 bent. Mr. Karl Krall has revised the work while passing 

 through the press. The publishers are Messrs. Whittaker 

 and Co. 



The first part of the new journal, Novitates ZoologiccB has 

 been issued. It is a large Svo, with 266 pages and four coloured 

 plates, while six others are deferred, to appear in part ii. An 

 excellent memoir, by Dr. Forsyth Major, on the small lemurs of 

 Madagascar {Microcebus., &c. ), commences the work ; then 

 follow articles by Mr. Rothschild (on a new pigeon, and on 

 some new sphinx-moths), and by his two assistants, Dr. E. 

 Hartert and Dr. K. Jordan, on various birds and insects. The 

 organ of the Tring Museum has made a good start, and 

 promises to be of great interest to zoologists. 



Lovers of nature will be glad to know that the supposed 

 dissolution of our old contemporary, Science Gossip, after nearly 

 thirty years' prosperity, proves to be only a case of suspended 

 animation, and that its familiar face will again be seen in public 

 after the 25th inst. In future Science Gossip will be under 

 the editorship of Mr. John T. Carrington and Mr. Edward Step. 

 The character of the paper as a medium between amateur natur- 

 alists, and for the recording of observations, will be fully main- 

 tained ; at the same time, it is intended to give it a higher 

 educational value by enlisting the aid of the leading men in 

 every department of natural science. Messrs. Simpkin, Mar- 

 shall, and Co. will in future be the publishers. 



In our issue of November 9, 1893, we gave a description of 

 some Hindoo dwarfs photographed by Colonel A. T. Eraser. 

 Dr. A. E. Grant afterwards suggested that the dwarfs were 

 afflicted with the disease known as pseudo-hypertrophic para- 

 lysis. Colonel A. T. Eraser writes to us, however, as follows : 

 • — "On observing Dr. A. E. Grant's letter in Nature for 

 January 4, I lost no time in sending him a copy of the dwarfs' 

 photograph, to which his reply states — ' It is evident they are 

 true dwarfs, and not subjects of the disease I alluded to. Their 

 heads and trunks appear to be of normal size, whilst their limhs 

 are stunted and deformed.' " 



Under the title, "Climates of the United States," Dr. 

 Charles Denison has prepared a revised edition, in a condensed 

 form, of his annual and seasonal climitic charts of the United 

 States. The book is published by the VV. T. Keener Co., 

 Chicago. It consists of twelve charts and eleven tables re- 

 presenting the climatic statistics of different sections of the 

 United States. The annual rainfall and temperature are shown 

 on one chart, the former by means of broken lines, and the 

 latter by the usual isothermals. A chart is devoted to the 

 illustration of annual cloudiness, and one to regimal elevations. 

 Upon the four charts exhibiting the isothermal lines for the 

 four seasons of the year, a number of arrows of three different 

 kinds are drawn, showing not only the directions of the pre- 

 vailing winds, but also the directions of winds likely to be 

 followed by rain or snow, and the directions of those that 

 usually herald fine weather. Tue average atmosphere humidi- 

 ties during different seasons of the year are clearly shown in 

 ei^ht degrees of colour. Altogether the book presents in a 

 handy form a mass of climatological information. 

 NO. 1269 VOL, 4q] 



The late Prof. Hertz could have no more permanent monu- 

 ment than that afforded by his work on the propagation of 

 electric energy through space, reviewed in these columns on 

 October 5, 1893. ^'^ English edition of the collected papers 

 contained in that volume has recently been published by Messrs. 

 Macmillan and Co., under the tiile "Electric Waves." Prof, 

 D. E. Jones is the translator, and he had the advantage 

 of Dr. Hertz's supervision and advice while the book was 

 passing through the pres-. In a preface, Lord Kelvin briefly 

 describes the development of the idea as to action at s. distance, 

 and concludes by pomting out that "absolutely nothing has 

 hitherto been done for gravity either by experiment or obser- 

 vation towards deciding between Newton and Bernoulli, as to 

 the question of its propagation through a medium, and up to 

 the present time we have no light, even so much as to point a 

 way for investigation in that direction." Lord Kelvin also calls 

 attention to the experimental work on electromagnetic waves 

 done previous to the publication of Hertz's researches, but 

 which do not detract in the least from their merit. The English 

 reading public will doubtless fully appreciate Prof. Jones' 

 translation of one of the most important works of this century. 



Th E polymeric modifications of acetic aldehyde form the subject 

 of an interesting and important communication by Messrs. Orn- 

 dorff and White to the January issue of the American Chemical 

 yournal. These remarkable substances, paraldehyde and 

 metaldehyde, have furnished the theme of many investigations, 

 but their nature and their relation to common aldehyde has not 

 hitherto been definitely established. In the older treatises upon 

 organic chemistry, no less than five difTerent polymeric forms of 

 aldehyde are mentioned, but the researches of Kekule and Zincke 

 resulted in the existence of only two being established, the liquid 

 paraldehyde and the solid metaldehyde. It was shown that care- 

 fully purified aldehyde suffers no change on heating or cooling, 

 or on being kept for a length of time, and that polymerisation 

 is always connected with the presence of certain substances, 

 such as hydrochloric and sulphuric acids or carbonyl chloride. 

 In most cases both forms are simultaneously produced, a low 

 temperature, particularly below o\ favouring the formation of 

 metaldehyde, and a higher temperature being more favourable 

 to the production of paraldehyde. The vapour density of paral- 

 dehyde was further shown to correspond to the triple formula 

 (C2H40)3, and it was assumed that three molecules of ordinary 

 aldehyde unite to form the closed chain compound, paralde- 

 hyde. The constitution thus arrived at for the liquid polymer 

 of aldehyde has since received remarkable confirmation from the 

 spectrometric work of Briihl, who found that the molecular 

 refraction of paraldehyde corresponded to that calculated upon 

 the assumption of the triple formula. Metaldehyde only differs 

 from paraldehyde in its physical properties ; chemically, the 

 two compounds behave precisely alike. The vapour density of 

 metaldehyde cannot be directly determined owing to its partial 

 dissociation into ordinary aldehyde when heated, hence its 

 formula has not hitherto been definitely known. Hanriot and 

 CEconomedes succeeded, however, in determining its density by 

 introducing a correction for the amount of ordinary aldehyde 

 produced, and their results indicated that the formula of this 

 solid polymer was the same as that of the liquid paraldehyde. 

 Orndorff and White have here taken up the subject, and show 

 that determinations of molecular weight by Raoult's method, 

 using phenol and thymol as solvents, point irresistibly to the same 

 conclusion, the molecular weight found being always in the 

 neighbourhood of 132, corresponding to three times 44) the 

 molecular weight of aldehyde. They have also rept-ated and ex- 

 tended the vapour density determinations of the former observers, 

 and have definitely settled the fact that paraldehyde and metal- 

 dehyde are isomers, both possessing the molecular composition 



