76 



Miscellaneous. 



ON THE DISCOVERY OF HYPERICUM LI N EAR1F0LI UM IN ENGLAND. 



Hypericum linearifolium was found by the Rev. Thomas Hincks 

 of Cork, among granite rocks near the banks of the Teign, Devon, 

 in the summer of 1838. Specimens are in his own collection and 

 in that of the Rev. William Hincks, F.L.S. of London, who lately 

 ascertained the species in looking over that part of his herbarium. 



The same plant is amongst Mr. Babington's acquisitions in Jersey 

 (see Annals, vol. ii. p. 348.), but it is interesting to know that it is 

 also found in England, and it is somewhat curious that so conspi- 

 cuous a plant has been so long overlooked. 



TEMPERATURE OF VEGETABLES. 



I have to thank M. Van Beck for the eagerness with which he 

 has repeated my experiments on the peculiar heat of vegetables. His 

 verification of the existence of this heat and of its diurnal period 

 places these facts in the number of those which may take a definitive 

 place in science, which, generally speaking, admits only that which 

 has been seen by more than one observer. 



M. Van Beck differs from me relative to a single fact of very little 

 importance. I mentioned, that upon placing in the open air as a com- 

 parative experiment, part of a living vegetable and a similar part 

 dead, the latter always appeared colder than the former : M. Van 

 Beck constantly obtained an opposite result. This opposition in the 

 results of our observations is perhaps caused by a difference in the 

 mode in which our experiments were prepared. M. Van Beck 

 plunged, as I did, the portion of vegetable which he meant to de- 

 prive of life into very hot water ; perhaps he then let it grow cold 

 in the open air, and thus lose by evaporation a part of the water 

 which moistened its surface ; whereas I cooled it by immersion in 

 cold water, and it was thus completely soaked with water when I 

 made the experiment. 



It will be seen that there must be more evaporation from it than 

 the less moist living vegetable portion, and that consequently, it 

 would necessarily be colder, whilst an opposite result might be ob- 

 tained when the vegetable portion, killed by the hot water, had been 

 able to evaporate the excess of water, which it had gained by re- 

 maining some time in the open air. Perhaps, also, the peculiar na- 

 ture of the vegetable parts may have an influence upon the difference 

 of the results in question. — Note of M. Dutrochet on M. Van Beck's 

 observations on the Temperature of Plants, Comptes Rendus, Jan. 13. 



MICROGRAPHY NEW OBSERVATIONS ON THE INFUSORIA OF ROCK SALT. 



In the ' Comptes Rendus' mention is made of a note received by 

 the Academy of Sciences from M. Marcel de Serres relative to the 

 observations which he is making on this subject along with M. Joly. 



In the specimens of rock salt of a tolerably decided greenish co- 

 lour brought from Cardona (Spain), the infusoria appear more rare, 

 smaller, and less distinct than in the specimens of a red colour be- 

 fore examined. 



This, says M. Marcel de Serres, finds an explanation in M. Joly's 



