_June._--During the whole of this month the wind blows constantly either from the S., W., or S.W. The jungles at this season are fatal to travellers, especially to Europeans, who would do wisely to avoid them and to pass this the rainy season at Bangkok, which is one of the healthiest of the tropical towns. _July._--In July sweet and refreshing breezes blow from the W. and S., but more rain falls than in June. There are sometimes very hot days, when the thermometer rises very high, but still in Siam this month is considered tolerably healthy. _August._--The same as July. _September._--This is a month of almost incessant rain, and it is very rare to have two or three consecutive fine days. _October._--Everything is inundated, some of the streets of Bangkok are transformed into canals, and the rivers everywhere overflow their banks. The first part of this month is as rainy as the preceding one. _November._--The Siamese now complain of the cold, but the Europeans rejoice in it, for the N.E. wind begins to blow. There are still some rainy days at the beginning of the month, and some hot ones. These transitions of temperature give rise to colds and catarrhs. At the end of the month the wind changes to the S.W. _December._--This is the best month to commence travelling on the rivers. Occasionally there is thunder and rain, but altogether it is considered a healthy month. METEOROLOGICAL REGISTER. METEOROLOGICAL REGISTER kept during the month of October 1861, and up to the sixth day after M. MOUHOT was attacked by fever. Louang Prabang (Laos).