I lO 



NA TURE 



[May 30, 1907 



chemistry appear to be able to overcome at the university 

 such early disadvantages ; and we learn that as a result 

 " most manufacturers have a high respect fcr the 

 advantages afforded by scientific education," and are 

 " ready to receive the young graduate with open cordiality." 

 The lot of the young chemist seems, indeed, to be a par- 

 ticularly happy one in the States in view of the " un- 

 precedented demand for good men." Statistics show that 

 the average salary of the graduates in chemistry of five 

 years' standing from the Case School of Applied Science 

 is about 3000 dollars per annum. At all colleges " there is 

 a far greater demand for graduates than can be supplied." 

 A powerful aid to research has recently arisen in the 

 immense funds devoted by many individuals to this pur- 

 pose ; amongst these the Carnegie foundation for the 

 retirement of teachers is mentioned, "as it relieves the 

 teacher during his earlier years from the anxiety of later 

 need and gives him courage to devote his residual energy 

 in some efforts for the advancement of knowledge." 



We have received a copy (printed for private circulation) 

 of the p'riday evening discourse delivered by Prof. A. H. 

 Church at the Royal Institution on April 12 on the 

 " Conservation of Urban Stone-work and Wall-paintings." 

 The most active among the agents tending to destroy the 

 stone-work of buildings of historical interest in large 

 towns is undoubtedly the sulphuric acid produced by the 

 combustion of coal used as fuel. It has been estimated 

 that at least half a million tons of sulphuric acid are 

 formed annually in London in this way. Rain charged 

 with the acid gradually converts the surface of the lime- 

 stone of public buildings (such, for instance, as St. Paul's 

 Cathedral) into gypsum, the increase of volume accompany- 

 ing the change being responsible, moreover, for a greater 

 or less degree of disintegration of the more delicate mould- 

 ings and tracery. An account is given by Prof. Church of 

 the remedial treatment adopted in such cases, based on 

 the use of a solution of baryta, which has the property of 

 re-cementing together the particles of the decayed stone- 

 work. The baryta acts by forming an insoluble sulphate 

 with the gypsum and liberating lime, which, under the 

 influence of carbonic acid from the air, regenerates the 

 original binding cement of the stone. This treatment is 

 applicable, not only to limestones, but also to sandstones 

 which were originally compacted by a calcareous cement. 

 The success attending its use is well illustrated by the ex- 

 perience obtained in the case of the Chapter House at West- 

 minster. " Before treatment a touch of the finger sufficed 

 to bring away the surface of the carving, afterwards the 

 stone was as sound as that newly quarried and harder." 

 To render the stone subsequently resistant to the action 

 of acids it may be covered with a suitable waterproofing 

 coating of paraflln wax. The conservation of mural 

 paintings or frescoes needs in each special case, according 

 to its character, a different process. A number of typical 

 cases of treatment are described. 



.\n interesting article on the life and work of Linnaeus, 

 by Mr. G. W. Murdoch, appeared in the Newcastle Daily 

 Journal of May 23. We congratulate that journal upon 

 being one of the few daily papers to publish a special 

 article upon Linnfeus on the 200th anniversary of his 

 birth. 



The Brazilian Engineering and Mining Review, which 

 has now reached its fourth annual volume, is a high- 

 class monthly technical journal published in English at 

 Rio de Janeiro. Looking through some back numbers 

 recently sent to us, we notice many articles of permanent 

 NO. 1961, VOL. 76] 



value regarding the mineral resources of Brazil, and, con- 

 tinued from number to number, a very important biblio- 

 graphy of the geology and palaeontology of Brazil com- 

 piled by Prof. John C. Branner. 



Several plates of illustrations of the zoology of the 

 Royal Indian Marine Survey ship Investigator have been 

 received from the Indian Museum. The illustrations in- 

 clude Crustacea (Malacostraca and Entomostraca) and 

 MoUusca, and have been prepared under the direction of 

 Dr. A. Alcock, F.R.S., Dr. N. .Annandale, and Mr. A. C. 

 MacGilchrist. 



A " Handy Guida to Photographic Requisites," which 

 is a conveniently arranged price list of photographic 

 apparatus, materials, and pure chemicals, has been pub- 

 lished by Messrs. Reynolds and Branson, Ltd., of Leeds. 



The much-discussed question of the structure of cyanic 

 acid forms the subject of a communication by F. Carlo 

 Palazzo and E. Carapelle in the Gazzetta (vol. .\xxvii., 

 ii., p. 184). It is pointed out that, while Nef's experi- 

 ments have shown that esters of the structure OR.CN 

 derived from normal cyanic acid do not exist, he still 

 adheres illogically to the view that the free acid and its 

 alkali salts are of the normal constitution. The argument 

 that Nef advanced, that the free iso-acid, CO : NH, would 

 be unstable in presence of water and undergo change into 

 the normal acid, should, on his own showing, from the 

 great power of addition possessed by the group .C N, be 

 reversed. Cyanic acid when esterified at so low a tempera- 

 ture as —5°, by means of diazomethane or diazoethane, 

 gives esters of the iio-type CO : N'R alone. In view of 

 the fact that the somewhat analogous o-pyridone gives 

 only oxygen esters under similar conditions, and of the 

 probability that isomeric change is excluded at so low a 

 temperature, it is concluded that the free acid and its 

 salts have the iso-structure. The same conclusion was 

 also recently arrived at by Chattaway and Wadmore using 

 a less direct argument. 



OU/i ASTRONOMICAL COLUMN. 



ASTRONO.MICAL OCCURRENCES IN JUNE: — 



Tune I. Mars. Apparent Diameter= 17 ""6. 



9. ih. Vesta in conjunction with Moon. Vesta 



0° 11' N. 

 10. 23h. 37m. Mercury in conjunction with 6 Geminorum 



(mag. 3 '2). Distance between centre of planet and 



star about 25". 

 12. I4h. Mercury in conjunction with Neptune. Mercury 



2° 51' N. 

 15. 8h. Mercury in conjunction with Jupiter. Mercury 



1° 41' N. 



18. I oh. 46m. Minimum of Algol (6 Persei). 



19. Uranus ■\° S. of v- Sagittarii (mag. S'2). 



22. 2h. Sun enters Cancer, Summer commences. 



23. Uranus J° S. of u' Sagittarii (mag. 5'0). 



24. Ilh. 40m. to I2h. 48m. Moon occults^ Ophiuchi 



(mag. 4-5). 

 26. Mercury at greatest elongation (25° 28' E). 



Magnitudes of Mira, December 14, 1906, to February 

 16, 1907. — The results of a number of naked-eye observ- 

 ations of Mira, made at the Radcliffe Observatory during 

 the recent maximum brightness of this star, are published 

 in the Monthly Notices (R.A.S.) for April (vol. Ixvii., 

 No. 6, p. 412), together with some notes on the star's 

 colour. 



The greatest magnitude, 2-06, during the period of 

 observation was recorded on December 27, when Mr. 

 Robinson found the colour of Mira to be similar to that of 

 a Arietis, i.e. yellow. Examined with the Barclay equa- 

 torial on January 11, the image of Mira showed red 



il 



