METEOROLOGICAL OBSERVATIONS. 357 



wings frozen together by the sleet that froze as it fell. 

 There were, he affirms, many dozen so disabled. WHITE. 



MIST, CALLED LONDON SMOKE. This is a blue mist, 

 which has somewhat the smell of coal-smoke, and as it 

 always comes to us with a north-east wind, is supposed to 

 come from London. It has a strong smell, and is supposed 

 to occasion blights. When such mists appear, they are 

 usually followed by dry weather. WHITE. 



REFLECTION ON Foa.* When people walk in deep white 

 fog by night with a lantern, if they will turn their backs to 

 the light, they will see their shades impressed on the fog in 

 rude gigantic proportions. This phenomenon seems not to 

 have been attended to, but implies the great density of the 

 meteor at that juncture. WHITE. 



HONEY DEW.f June 4, 1783. Vast honey dews this 

 week. The reason of these seems to be, that in hot days the 

 effluvia of flowers are drawn up by brisk evaporation, and 

 then in the night fall down with the dews, with which they 

 are entangled. J 



This clammy substance is very grateful to bees, who gather 

 it with great assiduity ; but it is injurious to the trees on 

 which it happens to fall, by stopping the pores of the leaves. 

 The greatest quantity falls in still, close weather ; because 

 winds disperse it, and copious dews dilute it, and prevent its 

 ill effects. It falls mostly in hazy, warm weather. WHITE. 



* The country people look with a kind of superstitious awe at the red 

 lowering aspect of the sun through a fog. " Cum caput obscura nitidum 

 ferrugine texit." MR. WHITE'S MSS. ED. 



f* Honey-dew is the exuviae of insects. They are little green aphides and 

 harbour under the leaves of trees, from whence their dew is dropped on the 

 leaves below. This is collected by bees and ants ; the latter are very careful 

 not to injure the insect, as I have frequently observed. It seems extra- 

 ordinary that so observant a naturalist as Mr. White should have been ignorant 

 of this circumstance. He mentions in one of his MSS. that one of his trees 

 was covered with aphides and viscous honey-dews. ED. 



J It will hardly be deemed a discredit to an observer so patient, so 

 accurate, and so faithful, as Mr. White, to mention, that his conjecture con- 

 cerning the origin of honey-dew is erroneous ; the subject has been elucidated 

 by the observations of Mr. William Curtis, who has discovered it to be the 

 " excrement of the aphides." See Transact, of the Linncean Society, vol. vi 

 No. 4. MITFORD. 



