27 



of the hive as possible. The evaporation is rapid and with very strong odour. 

 Henoe, if too mach used, the brood will be deserted 'by the workers and death 

 of the bees may take place. As soon as the dose has evaporated it is 

 renewed. 



As a preventive, naphthaline has been very favourably reported npon by 

 a number of writers ; and Gowan (73) states that he inspected very thoroagh- 

 ly a hive belonging to Merney which had been cured by this substance. 



Experiments. In our laboratory, crystals of naphthaline about the size of 

 a large pea were put into teat tuoes containing sloped agar, inoculated with 

 one loopfnl of spores, capped with tin foil paper and kept at 22° and 37° C. 



Results. After 48 hours — good growth in all tubes. Inoculated agar 

 plates containing a crystal of naphthaline likewise gave good growth in 24 

 hours at 37° , as did also the control tubes and plates. Hence, we con- 

 clude that naphthaline ha^ no antiseptic power ; and we are forced to look 

 upon its use rather doubtfully. It may, perhaps, act as a stimulant. 



(11) Formic acid. This substance was first suggested by Dennler in 

 1885 (74), but he did not ascertain the strength in which it could be used. 

 Sproule (75) states, that since the year 1882 he had successfully treated foul 

 brood with formic acid. He was the first apiculturist to use the remedy an<f 

 give the treatment. The solution used is pure acid, 10 parts ; water, 90 

 parts ; and the treatment is as follows : — 



A part of the comb is taken froaa the hive and as many bees as possible 

 are shaken from the diseased comb ; and then two or three empty combs are 

 used, into one of the sides of which 100 grams of the solution are poured, 

 while it is held inclined so as to allow the liquid to run into the cells and stay 

 there. These combs are placed on each side of the brood, the side containing 

 the solution next the brood. Eight or ten days after, an inspection is made ; 

 and if there is no cure, the dose is> renewed and continued every week until 

 the cure is complete, whioh is often after the first treatment. In fact the 

 disease rarely resists the second or third application. To hasten the cure, 

 this remedy can be given in the food of the bees — a teasp^onful to a litre of 

 syrup. 



Experiments Formic acid probably has an important rdle to play in the 

 keeping properties of honey. As long ago as 1878, formic acid was found in 

 honey ; and Muhlenhofi' (76) observed that when honey is not intended for im- 

 mediate use, the bee deposits in each cell a drop of formic acid, secreted by 

 the venom glands, and then seals the cell. Erlenmeyer (77) says that formic 

 acid of the strength of 1.205 gr. to a thousand parts of water was antiseptic, 

 Planta (78) refutes Muhlenhoff's idea that 100 grams of sealed honey con- 

 tains ,0186 grams of 22% formic acid. " 100 grams is the capacity of 165 

 worker cells, but the smallest droplet of venom contains at least .0254 grams 

 of formic acid, which would make for 165 cells, 4 1910 grama ; that is to say, 

 200 times more than there is in reality." This opinion is, however, contrary 

 to one expressed before by the same wiiter, in the year 1884 (79). 



Formic acid seems to help bees to ward oft the disease, especially when 

 we supply it to them ready made ; and that found in certain kinds of honey 

 has probably an antiseptic efi'ect. Two samples of clover honey and two 

 samples of buckwheat honey were analyzed in our chemical laboratory with the 

 following results : — 



1 Buckwheat honey 15 grains of formic acid in 100 grains of honey. 



2 " C 17 " " " " 



1 Clover honey 0579 



2 " 0.C57 " " " " 



