5^6 PRACTICAL BEE-KEEPING. 



contract their abdomens (a movement wMch may be generally seen when 

 &ny bee is at rest), which movement draws in and expels air by certain 

 holes in their sides, called spiracles, and by which they breathe. The 

 more rapidly this breathing is carried on the more (oxygen) air is brought 

 into contact with the honey they have eaten, the more of it is consumed, 

 and the greater the heat evolved ; but as the heat is in proportion to the 

 honey consumed so is it in proportion to the noxious gas (carbonic acid) 

 produced and the water thrown into the hive, as a reference to the rough 

 table, in which the essential oils of the honey, which are verv small in 

 amount, are disregarded for simplicity sake : 



9ozi. water := 9oz. water. 



6oz. carbon = 6oz. carbon. 



lilb. honey 



8oz. oxygen ) _ g^^_ ^^^^_ 



loz. hydrogen 



16oz. of oxygen from the air being united with the 6oz. carbon, we obtain 

 22oz. carbonic acid gas, which with the liberated 18oz. water are thrown 

 into the air of the hive by the consumption of 24oz. of honey^ 



Omitting to notice the water for the present, let us trace the 22oz. of 

 •carbonic acid gas, occupying about twelve cubic feet at ordinary tempera- 

 tures. In a Woodbury hive, for example, which holds about 1900 cubic 

 inches, the combs, stores, frames, and bees, would fill 1400 cubic inches, 

 so that the air space would not be greater that a quarter of a cubic foot ; 

 the carbonic acid, therefore, produced from the consumption of IJlb. oi 

 honey would fill the available space in the hive forty-eight tiraes. JToi 

 is this all : the air is pnly one-fifth by measure oxygen, the other four- 

 fifths being nitrogen, and ihe carbonic acid occupies the same space 

 precisely as the oxygen which united with the carbon to produce it, so 

 that we find if the whole of the oxygen of the air Introduced had been 

 converted into carbonic acid by union with carbon, the air in the hive 

 must have been entirely renewed 240 times ; and, further, the presence oi 

 carbonio acid in large amount is so deleterious, even to insects, that 

 probably not more than ten per cent, at the most of the oxygen could 

 be utilised in the production of carbonic acid, shutting us up to the con- 

 clusion that the consumption of l^lb. of honey needs the passage through 

 the hive of not less than 600 cubic feet of air, or, in other words, needs 

 the complete renovation of the air of the hive 2400 times. We have 

 previously stated the average loss in weight of a wintering colony in 

 which breeding is suspended is less than 21b. per month, or about loz. 

 per day, and this is irrespective of the number of bees, as we shall 

 presently show. loz. of honey, or one-twenty-fourth of IJlb., requires for 

 its conversion into carbonic acid one-twenty-fourth of 600 cubic feet, or 

 25ft. of air, or, which is the same thing, that the air of the hive should 

 be changed 100 times per twenty-four hours, or about every fifteen 

 jninutes. The escaping vitiated and damp air from the hive carries away 



