On making Tea. 345 
eye contributed to make them impress the mind asone. In 
the house where [ then lived was a marble chimney: piece, 
the upper horizontal block of which was fluted vertically 5 
and the ridge between each concavity of the fluting was 
about as wide as the concavity itself, When [ looked at 
this range of fluting at the distance of about nine inches, 
and directed the optic axes to it, I saw of course every 
ridge and concavity distinctly, and judged righily of the 
distance. Adjusting the optic axes as to an object a little 
further off, I discerned the fluting confusedly and all dou- 
ble, the ridges interfering with the concavities 5 which was 
accompanied with the uneasy sensation of squinting. But 
on widening the direction of the optic axes still more, as to 
an object about eighteen inches distant ; (namely, just so 
far that the duplication of the images should correspond 
successively; that is, so that the first ridge and concavity 
of the fluting, as seen by one eye, should fall in with the 
second ridge and concavity, as seen by the other;) the 
fluting appeared as distinct and as single as at first; but it 
seemed to be about double the distance from the eye that it 
really was, and to be magnified in proportion; nor had J, 
in this case, any sensation of squinting. As the parts of 
the fluting, though i in general much alike, were not exactly 
so every Bhere in colour and minute circumstances, there 
appeared in some places a slight confusion from this dissi- 
milarity of the images but ‘that trifling confusion had no 
manner of effect on the mind’s judgement of the images, 
which looked as perfectly single, as when the fluting was 
viewed with the optic axes so directed, that the ridges and 
concavities seen by one eye corresponded with the same 
ridges and concavities as perceived by the other. No idea 
was suggested, but that of a range of fluting larger and more 
distant than it was in fact. This experiment { frequently 
repeated, and always with the same effects. 
LVII. The Correctness of popular Observations illustrated 
in the Directions commonly given for making Tea, 
Parosorners will frequently find reason to follow the 
advice of Bacon, who recommends them to avoid a hasty 
contempt of popular opinions. The mass of mankind will 
be found with few exceptions perfectly correct in points of 
observation, however erroneous the conclusions may be 
which they sometimes deduce from their premises. Men 
of science are too apt to treat as vulgar errors, facts Wine 
) 
