GiiO 
on the road all of a sudden it became so cold that it was 
tit to take the face off one. I never felt it colder at Christmas. 
When we had got about fifty yards, all on a sudden it 
was quite hot and sultry, and I can compare it to nothing 
but going in the depth of winter into a stove, (i.e., a hothouse). 
That heat, in my opinion, is the cause of the potato 
disease." Without entering upon the good man's theory of 
potato disease, here, I think, is clearly an electrical discharge 
producing winter's cold " fit to take the face off one" in the 
region of its action, and then, by the condensation of the 
atmosphere at the margin of the region of discharge, 
causing the free heat which is compared to that of a hot- 
house. The sudden production of the cold and its very 
limited extent shewn by the man's rapid emergence from it 
to intense heat, cannot, I think, be accounted for in any 
other way. 
The absence of lightning (i.e., atmospheric matter heated 
to visibility) is no objection against this view, but rather a 
confirmation of it. Had the intensity of the electric dis- 
charge been greater, so that light was produced, the vapour 
present in the air must have been converted into ice by a 
more intense cold than was experienced, and hail or snow in 
the cold space would have resulted. But the fact of the 
cold being described as no more intense than that of an ordi- 
nary winter day (which need not in fact be near the freezing 
point, as, on a summer night, far less cold would appear 
relatively greater) requires the absence of light as part 
of the electric phenomena. 
During a thunder storm which occurred on the 16th of 
June, 1858, about five p.m., in the neighbourhood of 
Mirfield, in Yorkshire, much damage was done by the 
hailstones which fell ; many of these were of very large 
size, some were picked up after the storm which measured 
