aged negeess. 
493 
hare been describing, there was any mixture of these two 
species of light. The variations in intensity took place at 
considerable altitudes ; the light was white, and not coloured ; 
steady and not undulating. Besides, the Aurora Borealis 
is so seldom visible within the tropics, that during five years, 
though almost constantly sleeping in the open air and 
observing the heavens with unremitting attention I never 
perceived the least traces of that phenomenon. 
I am rather inclined to think that the variations of the 
zodiacal light are not all appearances dependent on certain 
modifications in the state of our atmosphere. Sometimes 
during nights equally clear, I sought in vain for the zodiacal 
light, when, on the previous night, it had appeared with 
the greatest brilliancy. Must we admit that emanations 
which reflect white light, and seem to have some analogy 
with the tails of comets, are less abundant at certain 
periods? Researches on the zodiacal light have acquired 
a new degree of interest since geometricians have taught 
us that we are ignorant of the real causes of this phenome- 
uon. The illustrious author of “La Mecanique Celeste” 
has shora that the solar atmosphere cannot reach even the 
planet Mercury; and that it could not in any case display 
the lenticular form which has been attributed to the 
zodiacal light. We may also entertain the same doubts 
respecting the nature of this light, as with regard to that 
of the tails of comets. Is it in fact a reflected or a direct 
light r 
We left the plantation of Manterola on the 11th of Peb- 
ruary, at sunrise. The road runs along the smiling banks 
of the luy ; the morning was cool and humid, and the air 
seemed embalmed by the delicious odour of the Pancratium 
undulatum, and other large liliaceous plants. In our way 
to La Victoria we passed the pretty village of Mamon or 
°e ,,° US yl 0 ’ c . elebr, ' lte <l m the country for a miraculous image 
A the \irgm. A little before we reached Mamon, we 
stopped at a farm belonging to the larnily of Monteras. 
A negress more than a hundred years old was seated 
before a small hut built of earth and reeds. Her age was 
known because she was a creole slave. She seemed Still to 
enjoy very good health. “ I keep her in the sun” (la tengo 
al sol), said her grandson; “the heat keeps her alive?” 
