Influence of the Temperature of Liquid Hydrogen on Seeds. 361 



" On the Influence of the Temperature of Liquid Hydrogen on the 

 Gerininative Power of Seeds/' By Sir William Thiseltox- 

 Dykr, K.C.M.G., CLE., F.E.S., Director of the Boyal Botanic 

 Gardens, Kew. Eeceived September 28, 1899. 



The ' Connotes Bendus ' for August 28 (p. 43-4) contains a communi- 

 cation from Professor Dewar to M. Henri Moissan, " relative a la 

 solidification de l'hydrogene." It concludes with the following sentence, 

 which may be easily overlooked : — " Des graines refroidies dans de 

 l'hydrogene liquide conservent tout-e la propriete de germer." 



This is the first announcement of an interesting experiment in which 

 Professor Dewar did me the honour to ask me to assist him. He has 

 further suggested to me to put on record the facts, as far as they came 

 under my observation, and any physiological conclusions to which they 

 seem to point. 



"With this suggestion I have no alternative but to comply. Botanists 

 will naturally expect some more detailed account than is contained in 

 the brief announcement which I have quoted. But as my share in the 

 research has been of the smallest, I should have much preferred that 

 Professor Dewar should have given the result of the whole investiga- 

 tion himself. 



When Professor Dewar first suggested the experiment to me, he 

 pointed out that it would be a costly one, that it would only be possible 

 to operate on very small quantities of seeds, and that the number of 

 kinds must also be few. 



The dozen seeds experimented upon by Messrs. Brown and Escombe, 

 which were submitted to the temperature of liquid air, were apparently 

 selected as belonging to different natural families, and also in some 

 degree as to their composition.* My choice was much more restricted. 

 I took two out of their list for the sake of comparison ; Barley and 

 vegetable marrow. I added wheat, which had more than once been made 

 the subject of experiment. This gave me two farinaceous seeds and one 

 oily one. I then took shape and bulk into account. Wheat and 

 barley are roughly ellipsoidal and medium in size. The vegetable 

 marrow is relatively large but flattened. I therefore added another 

 oily seed, mustard, which is small and spherical. I followed Messrs. 

 Browne and Escombe in taking a pea, which is also spherical in shape 

 but nitrogenous in composition. Finally I sought a very minute seed, 

 and pitched upon musk. 



The list then ultimately stood : — 



* < Boy. Soc. Proc.,' vol. 62, p. 161. 



