proceedings: botanical society 589 



range of pressure. Although comparatively little systematic investi- 

 gation of this domain has yet been made, several conclusions seem now 

 to be justified; the more important are as follows: Increase of pressure 

 raises the melting point (with but two known exceptions — bisnmth and 

 ice 1), the change produced being progressively smaller for each suc- 

 cessive pressure increment; but there is no reason for believing that 

 there is either a maximum melting point (as had been postulated by 

 Tammann) or a critical end-point solid-liquid. Change of pressure may 

 either raise or lower a transformation temperature (solid —^ solid) or a 

 solubihty; this implies that change of pressure may alter the number 

 and nature of the substances crystallizing out from a cooling solution 

 containing several components. Increase of pressure produces a de- 

 crease of electrical resistance of all the pure metals investigated (bismuth 

 excepted) , but increases the resistance of the alloys ; the change of resist- 

 ance of manganin or therlo is the most convenient means of measuring 

 high pressures accurately. Change of pressure displaces the position 

 of equilibrium of a chemical reaction, especially in reactions involv- 

 ing a vapor phase, since it has such a marked effect upon the con- 

 centration of the vapor. The communication was discussed by Messrs. 

 Buckingham, Sw^ann, Bowie, and Humphreys. 



Mr. L. J. Briggs then spoke on The Australian meeting of the British 

 Association for the Advancement of Science. The meeting was made pos- 

 sible through the generosity of the Australian Commonwealth, which 

 placed at the disposal of the British Association a fund to defray in 

 part the over-sea expenses of members and guests. Meetings were 

 held at Perth, Melbourne, Adelaide, Sydney, and Brisbane, the capi- 

 tals of the five states of the Commonwealth. The scientific meetings 

 were limited to Melbourne and Sydney. Numerous excursions were 

 arranged at each place. Free transportation was provided. on all the 

 railroads, and the over-sea members were entertained in each of the 

 cities. Of the many interesting papers presented before the physical 

 section, there was mentioned in particular the address of the President 

 of the section. Professor Trouton, on Absorption and adsorption; IVIr. 

 C. G. Abbot's paper on The variability of the Sun; Sir Ernest Ruther- 

 ford's paper on Gamma rays; and Mr. Moseley's paper on High fre- 

 quency spectra. 



J. A. Fleming, Secretary. 



BOTANICAL SOCIETY OF WASHINGTON 



The ninetv-eighth regular meeting of the Botanical Society of 

 Washington was held October 6, 1914, in the Cosmos Club. Forty 

 members and two guests were present. The followmg scientific pro- 

 gram was given: -7 / • . 



P. H. Dorsett, The botanical garden of Rio de Janeiro, Brazil (with 



lantern). / • u i 



W. F. Wight, Andean origin of the cultivated potato (with lantern 



and specimens). 



Both papers are to be published elsewhere. 



