512 Dr. R. A. Smith on the Examination of Air. [Dec. 13, 



(6) "We have seen in (4) that metals may be deposited on a thermo- 

 meter bulb and then deprived of a determinate part of their electro- 

 strictive power, and that there is an experimental possibility of deposit- 

 ing them with none of this effect. We are therefore in a position to 

 compare, one with the other, the two states of the same metal. The 

 electrostricted metal (submitted, as may have been the case, to more than 

 a hundred atmospheres' compression) must oppose the effect of a solvent 

 much more than that which is soft and no longer the subject of electro- 

 striction. In other words, a gramme of the former should require more 

 of a reagent to dissolve it than should the latter, under the same con- 

 ditions. But this excess corresponds to a known amount of electro- 

 strictive effect, which, again, is known in atmospheres pressure. We 

 ought therefore to be in a position to measure chemical effect in atmo- 

 spheres pressure. 



My best thanks are due to Professor Sir William Thomson for the 

 loan of an Andrews's apparatus ; to Professor George Forbes, for a 

 pressure machine ; and to Mr. W. H. Walenn for much practical advice 

 in connexion with electro-metallurgy. 



II. "The Examination of Air." By R. Angus Smith, Ph.D., 

 F.R.S. Received August 11, 1877. 



It is now many years since I first began to examine air so as to obtain 

 decidedly those bodies which have from the earliest times been sup- 

 posed to exist in it, bringing with them, on certain occasions, some 

 of the worst results. About eight years ago (that is, in 1869), after 

 giving a short summary of some of my work in the Journal of the 

 Scottish Meteorological Society, I used these words : — " For a satisfactory 

 investigation of the subject, one must look to the multiplication of these 

 experiments, and perhaps to the establishment of a department at some 

 Observatories for Chemical Climatology and Meteorology." 



Afterwards, in 1872, 1 published an octavo volume on Chemical Clima- 

 tology, embodying many of my results, and intended to be a beginning of 

 work to be continued by a public body. Indeed some of the work was 

 done whilst I was acting under the Government and was published in 

 Government Reports. It was often my intention to begin a movement 

 which might result in a fuller recognition of the claims of Chemical 

 Climatology ; but I have not gone further than speaking of it to Mr. 

 Scott, and proposing it to the Local Government Board, since the 

 time when I published the proposal alluded to ; at least I may say I 

 have not gone further in a distinct public manner. 



I should have been glad had my work caused in this country a beginning 

 such as has been made lately at the observatory of Mont Souris, at Paris, or 

 at least resembling it ; and I blame myself for not pushing forward the idea, 



