Insects. 1993 



little doubt that it is to the contact of these two currents that the deposition of mois- 

 ture at the entrance of the hive is due. In order to ascertain the quantity of fluid 

 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 suc- 

 cessful. During eleven and a half hours of the night of the 1st and 2nd of Septem- 

 ber, 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 tip 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, as on the preceding morning, was 10*5° Fahr. above that of the open at- 

 mosphere, and 2 - 5° above that of the top of the hive. At six o'clock of the evening 

 of the same day, when the temperature was sinking, and was then only 539 Fahr., 

 that of the vapour in the phial, taken as before, was only 59°. The hive had then 

 become quiet for the night, and its temperature was reduced. The temperature of 

 the expelled air was thus shown to depend much on the degree of activity or quies- 

 cence of the bees, and consequently on the greater or smaller amount of their respira- 

 tion. The bees were now in a state of rest, and respired but little; while in the 

 morning they were becoming active, and preparing to enter upon their labours. 

 During this night the temperature of the atmosphere sunk down to 32° Fahr. ; and 

 when I again examined it in the morning, September 4th, at six o'clock, it had risen 

 only to 41 '5° Fahr. The hive was then quiet ; the bees had been reposing all night, 

 and were disposed to pass into their state of semi-hybernation. The temperature of 

 the interior, at the top of the hive, was then only 54° Fahr., and that of the vapour in 

 the phial, even at the entrance-hole of the hive, was but 59° Fahr. ; and the quantity 

 of vapour condensed within the phial scarcely amounted to so much as three minims. 

 These concordant circumstances seem to prove that the vapour expelled from the hive 

 results in chief part from the respiration of the bees, and the extraneous transpiration 

 from their bodies ; that this is most abundant when the bees are most active and are 

 respiring freely, and when the greatest amount of heat is evolved by them. On the 

 contrary, as the activity of the bees is diminished, the temperature of the hive becomes 

 reduced and the quantity of air deteriorated, and the vapour expelled is lessened. 

 And may we not also conclude from the fact, that the vapour, which thus seems to be 

 the result of respiration by the bees, and which is condensed and deposited as it issues 

 forth, holds in solution a superabundance of carbonaceous matter, which is deposited 



