November 20th.  An eclipse of the sun, which I had anxiously hoped to observe with a view of determining the longitude, happened this morning, and, as often took place in this cloudy climate, the sun was covered four minutes before it began.  When it shone forth the eclipse was in progress, and a few minutes before it should (according to my calculations) have ended the sun was again completely obscured.  The greatest patience and perseverance are required, if one wishes to ascertain his position when it is the rainy season.

Before leaving, I had an opportunity of observing a curious insect, which inhabits trees of the fig family (’Ficus’), upward of twenty species of which are found here.  Seven or eight of them cluster round a spot on one of the smaller branches, and there keep up a constant distillation of a clear fluid, which, dropping to the ground, forms a little puddle below.  If a vessel is placed under them in the evening, it contains three or four pints of fluid in the morning.  The natives say that, if a drop falls into the eyes, it causes inflammation of these organs.  To the question whence is this fluid derived, the people reply that the insects suck it out of the tree, and our own naturalists give the same answer.  I have never seen an orifice, and it is scarcely possible that the tree can yield so much.  A similar but much smaller homopterous insect, of the family ‘Cercopidae’, is known in England as the frog-hopper (’Aphrophora spumaria’), when full grown and furnished with wings, but while still in the pupa state it is called “Cuckoo-spit”, from the mass of froth in which it envelops itself.  The circulation of sap in plants in our climate, especially of the graminaceae, is not quick enough to yield much moisture.  The African species is five or six times the size of the English.  In the case of branches of the fig-tree, the point the insects congregate on is soon marked by a number of incipient roots, such as are thrown out when a cutting is inserted in the ground for the purpose of starting another tree.  I believe that both the English and African insects belong to the same family, and differ only in size, and that the chief part of the moisture is derived from the atmosphere.  I leave it for naturalists to explain how these little creatures distill both by night and day as much water as they please, and are more independent than her majesty’s steam-ships, with their apparatus for condensing steam; for, without coal, their abundant supplies of sea-water are of no avail.  I tried the following experiment:  Finding a colony of these insects busily distilling on a branch of the ‘Ricinus communis’, or castor-oil plant, I denuded about 20 inches of the bark on the tree side of the insects, and scraped away the inner bark, so as to destroy all the ascending vessels.  I also cut a hole in the side of the branch, reaching to the middle, and then cut out the pith and internal vessels.  The distillation was