594 PHILOSOPHICAL TRANSACTIONS. [aNNO 1/33. 



they be all true, it seems difficult to support it against them. Thus, for two 

 months together, viz. June and July in 1728, every night, several smooth 

 plates of brass were laid on the bare ground; and during these experiments, he 

 never observed the least impressions or traces of dew on the upper surfaces ; 

 whereas the lower were always covered with it. He also suspended these plates 

 by threads, in a horizontal position, and found the dew spread almost equally 

 over both surfaces, at the height of 3, 4, or 5 feet; at the distance of ] foot 

 and -i-) the lower was more bedewed; but at the heights of 1, 2, or 3 inches, 

 the lower was overspread with dew, while the upper had none. 



He however mentions some experiments which he made, and at first view 

 seemed to contradict his theory: for instance, when he used convex bodies, 

 whether round or cylindrical, he found the upper surface covered with dew, 

 and that, whether they were laid on the ground, or suspended at any height 

 from it. 



This observation is general, and extends to bodies of this kind, that are 

 only contiguous, as heaps of straw, hay or wool. It is to observations of this 

 kind, the common opinion of dews falling, owes its birth and main support. 



Since hoar-frost is only common dew congealed, he made some of the same 

 kind of experiments on that, with brass plates laid on the ground as before. 

 These likewise he found covered with this kind of frost below, but free on the 

 upper superficies, agreeably to his hypothesis. 



The author closes the dissertation with a curious inquiry into the nature and 

 origin of honey-dew. This he takes to be nothing but the excrements of some 

 insects which are to be met with, adhering to the lower superficies of the leaves 

 of plants ; and appeals to the evidence of sense for a demonstration. 



Experiments shown before the Royal Society with the Spiritus Fini yEtherem, 

 and the Phosphorus Urime. By Dr. Frokenius, F.R.S. N" 428, p. 55. 



Nov. 18, 1731, Dr. Frobeuius took a solution of phosphorus in the ethereal 

 spirit of wine, which he called liquor luminosus, and poured it into a tub of 

 warm water; on which it gave a blue flame and smoke, attended with so small 

 a degree of heat, as not to burn the hand, if put into it. — He poured some of 

 his ethereal spirit of wine on a tub of cold water, and set it on fire with the 

 point of his sword ; which being first heated a little, he touched with it a piece 

 of phosphorus lodged before-hand on the side of the tub. After the deflagra- 

 tion the water was cold. 



He then showed a very cxtiaordinary process with phosphorus glacialis urinas, 

 or stick phosphorus, of Mr. Ambrose Godfrey Hanckewitz. 



