October 22, 1891] 



NATURE 



601 



product of the latter operation. In order to obtain the free 

 compound itself, the silver salt was prepared by allowing the 

 distillate to flow into a solution of silver nitrate, and the preci- 

 pitated silver salt, after drying, was decomposed with sulphuric 

 acid. In a subsequent communication (comp. Nature, vol. 

 xliii. p. 378), Prof. Curtius, in conjunction with Dr. Radenhausen, 

 showed that the pure compound was a very volatile liquid, boiling 

 at 37°, and of fearfully explosive properties. In the current 

 number of the Berichtc, Drs. Noelting and Grandmougin, of 

 Miilhausen, publish a preliminary note, in which they describe 

 a new, and from the point of view of its constitution most 

 important, method of preparing the liquid. The phenyl ester of 



azoimide is the diazobenzene imide of Griess, CgHg — N^ | j 



\n 



just as chlorbenzene is the phenyl ester of hydrochloric acid. 

 In view of the great stability of the esters of aromatic radicles, 

 it was hardly to be expected that diazobenzene imide wou'd 

 yield azoimide upon saponification. But Drs. Noelting 

 and Grandmougin considered that it might be possible 

 to obtain the latter by decomposing a nitro-derivative of 

 diazobenzene imide by means of alkalies, inasmuch as the 

 introduction of nitro-groups generally effects a considerable 

 increase in the mobility of the acid radicle, rendering its removal 

 by processes of saponification much less difficult. They there- 

 fore prepared the dinitro-derivative of diazobenzene imide from 

 dinitro-aniline by means of the usual diazo- reaction — conversion 

 into the perbromide, and treating with ammonia. When treated 

 with alcoholic potash, this dinitro-diazobenzene imide readily 

 decomposes into the potassium salt of dinitro-phenol and azo- 

 imide. Upon acidifying the product of the reaction and subject- 

 ing it to distillation, an aqueous solution of azoimide passes 

 over, which niay be converted into the anhydrous liquid by the 

 method described by Prof. Curtius. The properties of the an- 

 hydrous azoimide obtained by this new method agree completely 

 with those detailed by Prof. Curtius. 



The second new method of preparing azoimide was com- 

 municated by Dr. Thiele, of Halle, at the Versammlung 

 deutscher Naturforscher und Aerzte, held in that city in Sept- 

 ember last. In the course of an investigation of the compounds 



/NII2 

 of guanidine, nitro guanidine was obtained, C.^N— NO^. 



\NH.2 

 Upon treating this compound with acetic acid and zinc dust, it 

 is reduced to amido-guanidine, a substance which forms well- 

 crystallized salts. By boiling the latter with soda, decomposi- 

 tion ensues, with formation of free hydrazine, N2H4, which may 

 be very conveniently prepared by this method. Upon subjecting 

 the nitrate to the diazo- reaction, the diazo -nitrate of guanidine 



/NH., 

 is obtained, C=N — N=N— NO,. This compound readily 



\nh 



breaks up on warming into two compounds, one of which is 

 azoimide, and the other a complex acid of the composition 



C— N N 



CN5H3, and the curious constitution | | || . The azo- 



NH2 NH— N 

 imide may be obtained by distillation in a manner similar to 

 that described above. 



The additions to the Zoological Society's Gardens during the 

 past week include a Bonnet Monkey {Macactts sinicus i ) from 

 India, presented by Mr. W. Harrow ; a Macaque Monkey 

 {Macacus cynoniolgus) from India, presented by Mrs. Cotton ; a 

 Common Marmoset {Hapale jacchus) from South-East Brazil, 

 presented by Mrs. Trelawny ; a Gannet {Stila bassana), British, 

 presented by Mr. J. Hitchman ; a Smooth Snake (Coronella 

 hevis) from Hampshire, presented by Mr. F. C. Adams ; ten 

 Smooth Snakes {Coronella htvis), born in the Gardens. 

 NO. 1147, VOL. 44] 



OUR ASTRONOMICAL COLUMN. 



Distribution of Lunar Heat.— Mr. Frank H. Very's 

 essay on the distribution of the moon's heat and its variation 

 with the phase, vhich gained the prize of the Utrecht Society of 

 Arts and Sciences in 1890, has recently been published. A 

 bolometer in connection with a very sensitive galvanometer was 

 used in the rest arch, and the plan has been to project an image 

 of the moon about 3 centimetres in diameter by a concave 

 mirror; and to measure, not the heat from the whole of this, 

 but only that in a limited part of it, from ^^ to 3V of the area of 

 the disk, the observations being repeated at different points and 

 at different phases. Measures made six hours after full moon 

 show that the east limb was hotter than the west limb in the 

 proportion of 92*2 to 88*9. In one observation, made a day 

 after full moon, the excess of heat at the east limb was much 

 larger. There i« a regular decrement of heat in passing from 

 higher to lower latitudes, and observations on this point appear 

 to indicate that heat is accumulated after many days of con- 

 tinuous sunshine. The heat in the circumferential zone of the 

 full moon differs from that of the centre by about 20 per cent. 

 In this respect, therefore, the thermal image is like the visual 

 one. There seems to be soir;e evidence that bright regions 

 radiate a little more than dark during the middle of the lunar 

 day ; but this is not quite proved, and with a low altitude cf 

 the sun the effect is reversed. A comparison of the curve 

 drawn by Zollner for the moon's light with that deduced from 

 Mr. Very's observations brings out the point that visible ra}s 

 form a much larger proportion of the total radiation at the full 

 than at the partial phases, the maximum for light being much 

 more pronounced than that for the heat. The diminution of the 

 heat from the full to the third quarter is shown to be slower than 

 its increase from the first quarter to the full. This result agrees 

 with that obtained at Lord Rosse's Observatory, and is direct 

 evidence of the storage of heat by lunar rock-. 



GEOLOGICAL SOCIETY OF AMERICA. 



^"HE Geological Society of America met at Washington en 

 •*• August 24 and 25. Owing to the death of the President, 

 Prof. Alexander Winchell, Vice-President Gilbert took the 

 chair. 



The meeting was opened with an address on the late President 

 by his brother, Prof. N. H. Winchell. Alexander Winchell 

 was born on December 31, 1824, in Dutchess County, N.Y., 

 and died at Ann Arbor on February 19 last. His work was 

 many-sided. He had studied to be a civil engineer; had a 

 strong leaning towards theology. He also read medicine and 

 was a fine mathematician. He loved music, wrote poetry, and 

 modelled in clay and plaster. As a financial resource he became 

 a teacher, and was very successful. He became famous by his 

 arguments on "The Bible History of the Creation," and pub- 

 lished in the Chriiiian Advocate " Adamites and Pre- Adamites," 

 an exposition of Scriptural and scientific harmony. For four 

 years he lectured on geology at Vanderbilt University. During 

 his long connection with the University of Michigan he 

 wrote many scientific articles of a popular nature, and did 

 a great deal to popularize geological science. The speaker 

 spoke eloquently of his dead brother's long and splendid con- 

 nection with the Ann Arbor University. His death was most 

 touchingly described. Oddly enough the last words he uttered 

 in public were these : " When I speak to you again it will be of 

 the inhabitants of another world." He had just finished his 

 weekly lecture, and referred in his closing sentence to the sub- 

 sequent lecture that was never delivered. He discovered many 

 new geological species, and many other geologists testified their 

 admiration for him by naming after him species they discovered. 

 His great work for the Geological Society was touched on, and 

 the speaker expressed his conviction that the next generation 

 would keenly feel the beneficent influence of his brother's work. 

 At the conclusion of the memorial Prof. Edward Orton, Dr. C. 

 A. While, and Mr. C. R. Van Hisewere appointed a committee 

 to draft resolutions expressive of the Society's regret at the deaih 

 of its President. 



Prof. Dr. Gustav Steinmann, of the University of Freiburg, 

 Germany, read the first paper, which consisted of the description 

 of a geological map of South America. A large copy of the 

 map was hung up beside the platform, and small replicas were 

 distributed among the audience. Dr. Steinmann, who is a 

 young, bearded, spectacled, typical German student, was sent to 



