Drs. G. F. Yeo and T. Cash. 



Observations, &c. {continued). 



Delira Dun : — Great Trigonometrical Survey. Synopsis of Results. 



Vol. X-XIII. 4to. JDehra Dun 1880. The Survey. 



Loudon: — Meteorological Council. Report to the Royal Society. 

 8vo. London 1882. The Meteorological Office. 



Bevan (G. Phillips) The Statistical Atlas. Parts 6-15. folio. 

 London 1881-2. The Publishers. 



Gore (G.), F.R.S. The Scientific Basis of National Progress, 

 including that of Morality. 8vo. London 1882. On the Electro- 

 lysis of Sulphate of Copper. 8vo. Birmingham. The Author. 



Holden (Edward S.) Studies in Central American Picture-writing. 

 8vo. Washington 1881. The Author. 



Johnson (Rev. S. J.) Projections of Eclipses of the Sun and Moon. 

 a.d. 1882 — a.d. 2000, &c. MS. The Author. 



Pole (William), F.R.S. A Study of the Problem of Aerial Naviga- 

 tion, as affected by recent Mechanical Improvements. 8vo. 

 London 1882. The Author. 



Tenison- Woods (Rev. J. E.) Thirty-two Excerpts from " Proc. 

 Royal and Linnean Socs., N". S. Wales," " Trans. Phil. Soc. 

 Adelaide," "Proc. Royal Soc. Tasmania," &c. The Author. 



" The Effects of certain modifying Influences on the Latent 

 Period of Muscle Contraction." By Gerald F. Yeo, M.D., 

 F.R.C.S., and Theodore Cash, M.D. Communicated by 

 Dr. Sanderson, F.R.S. Received June 15. Read June 16, 

 1881. 



Although the labour of many physiologists has been directed to- 

 wards the consideration of Latency, it seemed to us desirable that the 

 subject should receive a little addition in some of its details, and it 

 was with the object of thus filling up deficiencies, and at the same 

 time of studying systematically the effect of some of the agents which 

 modify the time of latency, that we undertook the investigations, the 

 results of which we desire to lay before the Society. 



In 1867 Helmholtz and Baxt* published the results of experiments 

 they had instituted touching the speed of conduction in motor nerves 

 as measured by the relative latencies obtained in a nearer and more 

 distant stimulation of a nerve-trunk (frog) or of the skin above it, 

 and in publishing their experiments of 1870 they drew attention to 

 the modifying influence of temperature upon such conduction. Thus 



* " Monatsbericht d. Berliner Acad.," 1967, s. 228, and 18/0, s. 184. 



