278 | Mr.NEwronr on the Aqueous Vapour expelled from Bee-hives. 
believe that this fluid results in part from the respiration of the bees, and the ` 
extraneous transpiration from their bodies, generated during the night in the 
form of vapour, which is condensed and deposited as it comes into contact 
with the cold night air during the ventilation of the hive. It has already 
been stated by Huber, that the vitiated air of the hive is removed by the 
fanning of the bees, and that by this process a double current of air is esta- 
blished. The respired air is removed by the one, while fresh air enters by the 
other. My own observations have fully satisfied me of the correctness of 
these statements ; and I have little doubt that it is to the contact of these two 
currents that the deposition of moisture at the entrance of the hive is due. 
In order to ascertain the quantity of fluid that is expelled from a hive in one 
night, I made an experiment, which, although not free from objections with 
reference to the hygrometric condition of the air during the night, satisfied 
me that the quantity is often very considerable. I cut off the bottom of a 
glass phial, and then ground the edges carefully so as to fit accurately to the 
front of one of my wooden hives: the phial was then affixed to the entrance- 
hole, with its contracted neck left open, so that all the air which escaped 
from and entered the hive passed through it. By this means a part of the 
vapour that was expelled from the hive was condensed. in the phial, and the 
experiment, to a certain extent, was successful. During eleven and a half 
hours of the night of the 1st and 2nd of September, from half-past six in the 
evening till six in the morning, there was condensed in the phial about a 
dram and a half of fluid, besides what had escaped from the open mouth of 
the phial in the form of vapour. The temperature of the vapour, within the 
phial, as it issued from the entrance-hole of the hive, at half-past six o'clock in 
the morning, was 69? Fahr.; that of the external atmosphere was then only 59?:5 
Fahr. The temperature of the vapour within the phial was ascertained at a 
distance of four inches from the hive, the thermometer being held free within 
the neck and not in contact. At eight o’clock on the following morning, 
when the temperature of the external atmosphere was 61° Fahr., the vapour 
in the phial was 71°%5 Fahr., while a thermometer inserted through the top 
of the hive, and which had remained untouched for several days, showed that 
the interior of the upper part of the hive was then only 69? Fahr. The bees 
at that time were perfectly quiet. Thus the expelled atmosphere of the phial, 
