THE AMERICAN BEE JOURNAL. 



279 



The Cause of Foul Brood. 



More than two tliousaiul years since,Aris- 

 totle described this terrible plajjue; it is, 

 therefore not of modern origin. This 

 disease, cansinjj larvie to die in tiie cells, 

 and creating a foul stench which permeates 

 the hive, bringing death to its inhabitants, 

 has been a subject for discussion for many 

 years; and anything that tends to throw 

 light upon it will be of interest to the read- 

 ers of TiiK AMEincAX Bee Journai^. Dr. 

 Schontield, of (ieruuvny, has lately made a 

 variety of experiments with it, and we pre- 

 sent our readers with the following extracts 

 from his paper, which has been translated 

 byMr. J. S.Wood: 



Dr. Dzierzon proposed, by the wish of the 

 editor (of Dienen Zeilung), at the last 

 (Vandreforsanilingen) exhi()ition at Salts- 

 borg, the following question: "What is to 

 be looked upon as decided relative to foul 

 brood, both as regards theory and practice, 

 and what remains now undecided?" But, 

 although he laid all his views and his 

 name's intiuence in the balance in favor of 

 the correctness of the rreusziske theory, he 

 must still acknowledge that the incontes- 

 table proof was wanting, as at the conclu- 

 sion of his answer he declared, "If also the 

 theory brought forward by Dr. Preusz 

 should prove correct, yea, even if it Is the 

 most probable, so is yet the question- 

 cause, the sickness's real nature— even now 

 enveloped in obscurity.'' Thus we stand 

 in relation to the problem which I previous- 

 ly stated: 



Firstly. It must incontrovertibly be prov- 

 ed that the spores of the fungus leave the 

 dried-up foul brood, and they must, inas- 

 much as they float in the air, be able to be 

 caught. 



Secondly. It must next be shown that 

 such fungus spores, that are caught in the 

 atmosphere, when placed on healthy larvis, 

 can grow and increase to an imcountable 

 number, until at last they kill the brood, 

 and so prove themselves the cause of the 

 sickness. 



Although the problem appeared difficult, 

 I went even confidently to the work. 1 

 wrote immediately to llerr Locher, in Sig- 

 maringen, and asked him for a little foul 

 brood. The ISth of June I received, enclos- 

 ed in a letter, so much as I could form into 

 a ball about the size of a pea. The sub- 

 stance was very dark, nearly black, moist, 

 and tenacious, and its odor was exceedingly 

 disagreeable. A careful examination under 

 the microscope proved the presence of fun- 

 gus of the same form as Micrococcus. Ilad 

 I, after having solved my problem, began 

 first to show that the sp()res could escape 

 through the fly-holes (entrances) of hives 

 containing foul brood, it would have been 

 necessary for me (in order to have obtained 

 such a hive) to dissolve the infectious sub- 

 stance in water, and therewith sprinkle a 

 comb containing healthy brood. It is most 

 l^robable that such a proceeding would have 

 failed, as the bees would most surely have 

 cast out the dead larv?e and pupae before the 

 artificially produced sickness had had time 

 to develop itself fully, and infect the whole 

 hive. In every case there would liave gone 



a much longer time by that means before 1 

 had arrived at the result. I had not, how- 

 ever, in the mean time the opportunity, as I 

 already wished to discuss my experiment at 

 Ilalle. I, therefore, immediately made the 

 experiment to catch the spores that were 

 escaping, and were floating in the atmo- 

 sphere, from the infected substance that 

 had been sent me, and thereafter use them 

 for infecting healthy brood. For this pur- 

 pose I constructed the following apparatus: 

 On a smooth-planed board I placed a bell- 

 glass, in the top of which was a round hole; 

 in this I fixed a glass tube two feet long; 

 there was also fixed a similar glass tube in 

 the board. In the top of the uppermost 

 tube was fixed a i)lug or cotton-wool, as also 

 in the under end of the bottom tube, and 

 the w^ool was not pressed tight, but so that 

 the air could circulate freely through both 

 tubes. 



The foul brood substance that I had re- 

 ceived from Herr Locher, was now placed 

 under the bell-glass on the 21st of June, and 

 left to dry slowly. If, then, the assertion 

 that the spores escaped in the air when the 

 substance was dry was correct, then it was 

 only necessary for me now and then to 

 place the apparatus by the window in my 

 study, and expose it to the full intiuence of 

 the sunbeams, as if the air in the bell-glass, 

 by the power of the sunbeams, was warmed 

 up to 40 deg., it must, by a well known phy- 

 sical law, escape through the uppermost 

 tube, while the cooler air from the floor of 

 the study must enter the bell-glass through 

 the bottom tube, and at the same time it 

 was quite as certain that therewithal the 

 spores of the fungus, that were carried by 

 the upward currant of air, would be caught 

 in the wool above. 



On the •5th of July, on which day the sub- 

 stance was quite dry, until the end of the 

 month, I got four plugs of wool, each of 

 which had served as the top plug for about 

 eight eays; besides these I had two pads of 

 wool, each of an area of about four square 

 inches, which I had placed inside at the top 

 of the bell-glass. 



Had the spores from the substance really 

 been escaping? and had the wool caught 

 them as they were coming out into the 

 world? All rested on the answering of 

 these questions; and examination gave the 

 following results: 



1. When quite a small portion of the wool 

 was washed in distilled water, and there- 

 after a drop of this water placed under a 

 microscope, it showed a considerable quan- 

 tity of fungus Micrococcus. 



2. If a plug of wool, as large as a pin's 

 head, was laid dry on a piece of glass there- 

 after moistened with distilled water, and 

 placed under the microscope, the Micrococ- 

 cus could be seen partly in the water, and 

 partly adhering to the threads of wool. 



3. if the wool was examined dry it was 

 difficult to see the Micrococcus, and it could 

 only be seen by aid of the strongest lens, 

 and through three objectives. 



4. Of gun-cotton, of which I had two 

 plugs, which were prepared with water as 

 sub. 1 and 2. Micrococci were to be seen in 

 still greater (|uaiititics than in the ordinary 

 wool, prol>al)ly because the one is finer and 

 better suited to retain the spores. 



Thus, by a practical method, I have solved 

 the first part of my in-oblem; and it is 

 without a doubt xirovcd. though in an un- 

 equal degree, that the spores of the fungus 



