TRANSACTIONS OF THE SECTIONS. 155 



trees ; it can be compared with the elevated valley of the Eugadin in the Grisons, but 

 the valley and the mountains on both sides are about twice as high. In a few days 

 we shall go out to Tibet by Oota Dhoora and Laptel. We go both alone, sending all 

 our followers to Badrinath. We shall be of course disguised as Bhotias. Manee, the 

 Putwaree of Johai*, and ten Bhotias with fifteen Joopoos, will accompany us. We 

 take with us a selection of the best and most portable instruments, and if it is in any 

 way possible we hope to go to Mansarower, the holy lakes of Tibet. The only thing 

 we have really to fear, is that the present war between the Tibetans and Nepalese 

 may interfere with our route. 



On the Amazon and Atlantic Water-courses of South America. 

 By Senor Susini. 

 Serior Susini, in his introductory observations, states, that of all the diplomatic 

 questions of the present period, the most important and the most valuable as regards 

 Spain is that of the free navigation of the above-mentioned majestic rivers and their 

 tributaries. The regions watered by the Amazonas, reclaimed from the savage tribes, 

 ferocious animals, and no.xious reptiles which now infest them, and traversed by the 

 ploughshare, miglit be capable of sustaining the population of the entire globe. The 

 district in question is pre-eminently adapted for the growth of rice, which commonly 

 yields there fortyfold, and which is reaped five months after being planted in the 

 ground, irrespective of season. Senor Susini describes generally the characteristics 

 of the South American climate and soil. 



STATISTICS. 



Notes on the Applicatioii of Statistics to questions in Medical Science, par- 

 ticularly as to the External Causes of Diseases. By W. P. Alison, 

 M.D. Edinburgh, D.C.L. Oxon. Emeritus Professor of Practice of Medi- 

 cine, Edinburgh, ^c. ^c. 



The object of this paper was to show that, notwithstanding the plausible objections 

 often made to statistical inquiries, as being applicable to the support of so many 

 principles, as to give little real support to any, there are various questions in medical 

 science, of the utmost practical importance, which admit of a perfectly satisfactory 

 solution in this way, and in no other; because the present state of science does not 

 enable us, nor afford anj' prospect of our being soon enabled to understand the inti- 

 mate nature either of diseased actions, or of the powers by which they may be 

 excited or counteracted ; in many instances, when, by simply empirical observation, 

 and comparison of numbers, i. e. by evidence truly statistical, although often not 

 formally expressed as such, principles may be established which are already amply 

 sufficient for practical application of the highest importance. 



The author referred to some observations of his own (in the ' British and Foreign 

 Medical Review,' for 185 1), as explaining why these useful applications of statistics 

 should more frequently be made to inquiries in Etiology, i. e. regarding the external 

 causes of diseases, than in any other department of medical science ; the objects of 

 these inquiries being usually simpler, involving fewer sources of fallacy, and re- 

 quiring less exercise of judgment, in order that they may be prepared for decision 

 in this way, especially when the observations may be made on organized bodies of 

 men, as on military and naval service, where all the conditions capable of affecting 

 the result are known to, and may often be varied by, the observers ; and further, he 

 directed attention particularly to the fact, that the positive observation as to an 

 alleged efi'ect following the application of the alleged external cause of disease, is 

 very often supported by a large body of negative observations, hardly appearing to 

 require expression in words, and therefore often overlooked, but truly essential to 

 the validity of the inference, and giving it a degree of authority resembling that of 



