VOL. L.] I'HILOSOPHICAL TRANSACTIONS. ] 97 



Scilly eastward as far as Liskerd, and towards the north as far as Camelford. At 

 Plymouth it was just sensible. In several places the houses shook, the windows 

 rattled, the floors lifted, the chamber-bells rung, the pewter, &c. on the shelves 

 were much agitated. Thus was this earthquake felt in towns, houses, and 

 grounds adjacent; but still more particularly alarming in the mines, where there 

 is less refuge, and consequently a greater dread from the tremors of the earth. 

 In these it was heard and felt at all depths, to 70 fathoms or more, and seemed 

 as below them. 



LXV. On the Sleep of Plants ; and of that Faculty ivhich Linneus calls Vigilice 

 Florum ; with an Enumeration of several Plants which are subject to that Law. 

 By Mr. Richard Pulteney of Leicester, p. 506. 



Acostaand Prosper Alpinus, who both wrote near the conclusion of the l6th 

 century, appear to be the first who recorded that nocturnal change in the leaves 

 of plants, which has since been called somnus. It is an observation indeed as 

 old as Pliny's time, that the leaves of trefoil assume an erect situation on the 

 coming of storms. The same is observable of our wood-sorrel ; and Linneus 

 adds, of almost all plants with declinated stamina. In the trifolium pratense al- 

 bum c. B. or common white-flowered meadow-trefoil, it is so obvious, that the 

 common people in Sweden remark, and prognosticate the coming of tempests 

 and rain from it. 



The examples of sleeping plants instanced by Alpinus are but few. That 

 author says, it was common to several Egyptian species; but specifies only the 

 Acaciae, Abrus, Absus, Sesban, and the tamarind-tree. Cornutus some time 

 afterwards remarked this property in the Pseudo-acacia Americana. From that 

 time it has remained almost unnoticed, till Linneus, ever attentive to nature's 

 works, discovered that the same affair was transacted in many other plants ; and 

 his observations have furnished us with numerous and obvious examples of it. 

 Mr. Miller mentions it in the medicago arborea Linn. Sp. PI. 778; and we may 

 add to the list two other common plants not mentioned by Linneus : these are 

 the phaseolus vulgaris, common kidney-bean ; and the trifolium pratense pur- 

 pureum majus, or clover-grass: in both which this nocturnal change is remark- 

 ably displayed. Doubtless the same property exists in numberless other species ; 

 and future observation will very probably confirm Dr. Hill's sentiment, that no 

 plant or tree is wholly unaffected by it. 



It is now more than 20 years since Linneus first attended to this quality in 

 plants. In his Flora Lapponica, when speaking of the trifolium pratense album, 

 as above-mentioned, he remarks, that the leaves of the mimosa, cassia, Bauhinia, 

 Parkinsonia, Guilandina, and others in affinity with them, were subject to this 

 change in the night-time : and he had then carried his observations so far, as to 



