October 26, 1893] 



NATURE 



631 



to chemical actions taking place in any substance, heat which has 

 been unable to escape has raised the temperature to the point of 

 ignition, a point at which slow combustion pisses into rapid 

 combustion with manifestation of incandescence ; and in speaking 

 of spontaneous combustion, we must clearly remember that it 

 represents merely the acceleration of an action which has been 

 going on slowly and surely, although our senses may have been 

 too deadened to detect it, and that if we wished to be hyper- 

 critical, "Unaided Ignition," or "Natural Ignition," would 

 be a far more correct term to apply to it than "Spontaneous 

 Combustion." 



UNIVERSITY AND EDUCATIONAL 

 INTELLIGENCE. 



Cambridge. — The following appointments in connection with 

 the scientific departments are announced : — Mr. Francis Darwin, 

 Reader in Botany, tn he Deputy Professor in the place of Prof. 

 Babinglon, who is still unable to lecture ; Dr. D. Mac.A-lister to 

 be .\ssessor to the Reqius Professor of Physics ; Dr. Hill, 

 Master ot Downing, and Dr. H. D. Rolleston to he Examiners 

 in Anatomy ; Dr. A. S. Lea and Prof. Schdfer to be Examiners 

 in Physiolo,:;y ; Dr. W. J. .Sollas and Mr. P. Lake (St. John's) 

 to be Examiners in Geol 'yy ; Mr. Skinner (Christ's) to bean 

 Examiner in Chemistry ; Prof. J. J. Thomson and Prof. G. F. 

 Fitzgerald (of Dublin) to he Examiners in Phy<ics ; Mr. A. 

 Sedgwick (Trinity) and Mr. \V. Bateson (St. John's) to be 

 Examiners in Zoology • Prof. Lewis and Mr. H. A. Miers to 

 be Ex.nminers in Mineralogy ; Mr. Seward (St. John's) and 

 Prof. D. E. Oliver to he Examiners in Botany. 



Prof. Sir R. S. Ball has been appointed an Elector to the 

 Isaac Newton Astronomy Studentshi|i--. 



The Moderators and Examiners for the next Mathematical 

 Tripos (Part I.) are Mr. Walsh (Jesus), Mr. Dawson (Christ's), 

 Mr. Burnside (Pembroke), and Mr. Whitehead (Trinity). For 

 the Second Part, Dr. Forsyth, Sir R. S. Ball, Prof. Lamb, and 

 Mr. H. F. Baker (St. John's) are to examine. 



Mrs. E. J. Moore, daughter of the late Colonel Fletcher, 

 has presented to the University her father's valuable collection 

 of Silurian fossils, in supplement of the Fletcher collection pur- 

 chased many vears ago for the Woodwardian Museum. 



The Clerk Maxwell Studentship in Experimental Physics, of 

 the value of about ;^i8o a year, tenable for three years, is 

 vacant by the resignation of Mr. W. Cassie, who has been ap- 

 pointed to a professorship at the Royal Holloway College. 

 Candidates must be members of the University who have been a 

 student for one term or more at the Cavendish Laboratory. The 

 names of applicants are to be sent to Prof. J. J. Thomson 

 before November 1 8. 



A grant of /loo from the Worts Travelling Scholars Fund 

 has been made to F. W. Keeble, Frank Smart student of 

 Caius College, to enable him to pursue botanical research in 

 Ceylon. 



An examination for scholarships and exhibitions in Natural 

 Science, of the value of ;^8o a year and under, will be held at 

 Trinity College on Tuesday, October 31. 



At the annual meeting of the New Decimal Association, on 

 October 18, Mr. Samuel Montagu, M.P., remarked that 

 there was a prospect of the United Stales adopting the 

 metric system as well as a decimal system of coinage. 

 Efforts had been made to induce Mr. Acland to instruct 

 inspectors to examine in the metric system in those schools 

 where it was taught, and, in a letter received from the 

 Education Department on the subject, it was said : " The 

 Code does not prescribe knowledge of the metric system, 

 but of the principles of that system— z'.c. of the dim.inulion of 

 quantities by tenths, and their increase by tens, with examples 

 sufficient to illustrate the conveniences of the system. Her 

 Majesty's inspectors are required to satisfy themselves that the 

 principles as thus defined are properly taught. It is proposed 

 to issue a memorandum to inspectors on the point at an early 

 date." 



SCIENTIFIC SERIALS. 

 American Joio-nal o; Science, October. — On endothermic 

 reactions effected by mechanical force, by M. Carey Lea. The 

 object of this investigation was to find whether the blackening 



NO. 1252, VOL. 48] 



effects of pressure upon the silver haloids and other salts could 

 be made immediately visible to the eye, instead of after the 

 application of a reducing agent. For this purpose the pressure 

 was increased to about a million pounds per square inch, or 

 about seventy thousand atmospheres. This pressure was 

 obtained by means of a vice actuated by a screw with six turns 

 to the inch and a lever three feet long. The nuts had to be 

 four inches in length to prevent stripping of the thread. The 

 jaws were specially constructed, and faced with steel welded on. 

 The materials experimented upon were wrapped in platinum or 

 silver foil, which remained unaffected by the pressure. Silver 

 sulphite and carbonate were moderately darkened by two days' 

 pressure, and silver salicylate considerably so. Salts of mercury 

 also showed pronounced effects, which prove that mechanical 

 force can bring about endothermic reactions corresponding to 

 those affected by light, heat, and other forms of energy. — Con- 

 ditions of Appalachian faulting, by Bailey Willis and C. Willard 

 Hayes. The authors discuss the antecedent conditions for the 

 development, the mechanics of step-folds and thrust-faults as 

 bearing upon actually observed Appalachian structure, and the 

 direction from which the compressing force acted. They come 

 to the conclusion that the latter was equal in opposite directions, 

 and directed north-westward and south-eastward. — On the 

 separation of copper from cadmium by the iodide method, by 

 Philipp E. Browning. The copper was precipitated from a 

 mixed solution by potassium iodide, and fiUered through an 

 asbestos felt, washed, dried at 120° C. and weighed. The fil- 

 trate and washings containing the cadmium were heated to 

 boiling, and sufficient sodium carbonate was added to complete 

 the precipitation. The precipitate was washed with hot water 

 until free from sulphate or iodide. The crucible containing the 

 cadmium carbonate was heated gently at first, then gradually to 

 ii higher degree until the white carbonate had changed to the 

 brown oxide. The method, as tested by. means of standard 

 solutions, is fairly accurate, and it is simple in manipulation. — 

 Also papers by Messrs. Foerste, Hidden, Wheeler, Eakins, 

 Williams, Penfield, and Marsh. 



Thi-; Amciican Meteorological Journal for October contains 

 an account, by A. L. Rotch, of tne establishment of a meteoro- 

 logical station at Charchani, near Arequipa, at an altitude of 

 16,650 feet, which is said to be the highest station in the world. 

 A sum of money was left to Harvard College Obervatory by 

 U. A. Boyden, lor the purpose of establishing an observatory 

 at a high station, and owing to the remarkable clearness of 

 the air at Arequipa, Peru, this situation was selected for the 

 purpose. The establishment is fully equipped with instru- 

 ments and is 8,050 feet above the sea; to the north east and 

 ten miles distant is the quiescent volcano of the Misti, 19,000 

 feet in altitude, and twelve miles north rises Charchani, 20,000 

 feet high. The meteorological station now in question has 

 been established just below the permanent snow line, and is 

 supplied with self-recording aneroid and thermometers. The 

 ascent from the permanent observatory, 8,600 feet below, can 

 be made by mule in about eight hours, and an assistant is en- 

 trusted with the duty of visiting the station periodically to 

 attend to the records. The results of the observations at both 

 stations will be published in the Annals of the Harvard College 

 Observatory, and will furnish a valuable addition to our know- 

 ledge of mountain meteorology. 



In the same number, Prof. G. E. Curtis gives an analysis of 

 the causes of rainfall, with especial relations to surface condi- 

 tions. Among these a principal question is whether forestation 

 increases and deforestation decreases the rainfall. The author 

 considers that the influence of forests has been over-estimated, 

 and that if they affect the rainfall, the amount has, in most 

 cases, not been greater than the amount of probable error in the 

 observations themselves, and therefore that the statistics give 

 no assurance that the effect is not an error of observation. If 

 the rainfall is increased it must be due either to an increase 

 of evaporation, and its subsequent precipitation over the 

 same region, or to the diversion of rain to the forest area, 

 which might have fallen elsewhere. 



SOCIETIES AND ACADEMIES. 

 Paris. 

 Academy of Sciences, October 16. — M. Lcewy in the 

 chair. — On the stability of equilibrium of the axis of the 

 gyroscopic top, by M. H. Resal.— On the partial differen- 

 tial equation presented in the theory of the vibrations 



