98 PEACTICAL BEE-KEEPING. 



this. The material burning is, like honey, composed of carbon, oxygen, 

 and hydrogen ; and, as in our table, oxygen united with carbon gives 

 carbonic acid, while oxygen and hydrogen unitiig produce water, which 

 may be taken from the flame by passing through it a cold knife upon 

 which the generated water will collect in dew. 



Seeing, then, the relation of honey and pollen as heat and flesh formers 

 respectively (see page 61), it is interesting to observe that the laxvte or 

 young and growing grubs as chyle feeders (see page 5) are not producers of 

 heat, and need the brooding of the nurses in order to have their temperature 

 so maintained that the nutritive functions may be continued. A dense 

 comb of grubs is as quickly chiUed as a comb of store ; and should they 

 be from any cause exposed to a very low temperature, death soon works 

 amongst them, producing " chilled brood " (see page 90). Whilst the popu- 

 lation is strong and the external temperature not too low, bees ventilate 

 their hives so thoroughly by placing fanners in different parts, and 

 especially near the hive mouth, to keep up a constant current by uninter- 

 ruptedly flapping their wings, while they hold on with their feet, that 

 the air of the interior is scarcely less pure than that without. Very 

 strong colonies, if visited at an early hour on chilly spring mornings, 

 wiU be found pouring out a stream of condensed vapour (popularly steam), 

 while the water from it will continue to drip from the alighting board, 

 and if a lighted candle be placed in the outcast of air it will be at once 

 extinguished. But in biting weather the little labourers, whose earnest 

 efforts to procure an untainted atmosphere may often well shame us, are 

 driven from the door to the cluster, where, closely huddled together, they 

 resist a temperature in which a single bee could no more continue its 

 vitality than could a single coal continue to burn in the firegrate ; and, as a 

 oonsequence, summer ventilation other than that through the hive mouth 

 is not only unnecessary, but would sometimes be prejudicial; but in winter, 

 as the facts just stated show, the case is widely different. Then the cluster, 

 which, as we have already stated, maintains a high temperature within 

 itself, throws up the heated air respired from many thousand spiracles,* 

 and this, striking against the hive roof, if there not allowed to 

 escape, remains until cold to descend upon the inmates. It can only 

 escape at all by the law of gaseous diffusion, which causes aU aeriform 

 bodies to commingle. It at best passes from the door very slowly, and 

 not until the air within is all more or less carbonised. Bees stifled by 

 contracted hive mouths, and aU apertures carefully closed above, are in 

 the condition of coke in an Arnott stove with the draught hole closed. 

 The process of heat production cannot go on, and the bees, stupified by 



♦ It is worthy of remark that when the hees thrust themselves into the cells 

 head first the spiracles or hreathing holes in the abdomen rtmaiu exposed to the 

 air, -which passes up slowly through the cluster. "Whilst so placed, therefore, their 

 breathing is not interfered with. 



