26 BULLETIN 810, U. S. DEPARTMENT OF AGRICULTURE. 
EFFECT OF DRUGS ON EUROPEAN FOULBROOD 
Preliminary experiments have been made to obtain data relative 
to the effect of drugs on Bacillus pluton. In conducting the experi- 
ments a suspension of the stomach contents of larvee sick or recently 
dead of European foulbrood is made in an aqueous solution of the drug. 
This is added to diluted honey and healthy brood is fed this sus- 
pension. In some instances the direct and in others the indirect 
method was followed. In Table XV are summarized the experiments 
which were performed: 
TABLE XV.—The effect of drugs on EHuropean foulbrood 
Date of experiment. Drugs. Strength. Results of inoculation. 
1916 
Dis liver eet = a= Aaa = See Betanaphtholess222--- 2s se-e- ee 1:2000 
Ny BASS Soon son ceacoanes) cance OE Siggeintgs oc consduae soSse¢ 1:1000 
d [iba Ves (Shes Sener rere 0 (Ne See eS be co seme Eeneease 2:1000 
dimli7a Uber Se nee Be Ree Carboliclacid= =. 4224-2 =.= 25 -eee- ig 
JUNE Zoos ease see eee do Sis EOOOdE San 5eSeecdsecded 1:1000 
Oaneueses cesdeseoe Benen hes Sono dodbecseocuoauaooes 2:1000 
May toltss amr ccr es ee Oil of eucalyptuSss-os--22-2—es-= 4:1000 
July lees eek cece cel eeeee Gls Soa eeecusoSusoon cde sHeES 4:1000 
UUM ON ae Sone cere Sees MOLMMCG A CIOs eee saee ee eee eer 1:1000 
Duilyoul ee eit ee ee ae o4|- ase Wtigas Sah Seen ssoceeeenssSsse- 3:1000 |?European foulbrood produced. 
DOS 82 sce pe eS cea oa Salicylicacid® 222-4 2 te a 1:2000 
IM ye Se Acie eyo sees errata DOS eee tee cane eee ae 1:1000 
UMNO Ta S BS oho niste oe nays ore GOs Sas Sees eee hee 2:1000 
tb sil by i ie a in rae ee at Salolisccss sateen eee ee eee 1:2000 
Mayisle cts eee EE Sela Go. Be tee eee a 1:1000 
JUNC Ht Seamer see seme leat GOre th sees tie ee eee 2:1000 
Guily lee eye ceet aoe Quinine seca eat sae 2:1000 
Mia yeoliye seen sae ee Sac eee GOB eee ee eee 4:1000 
WU /She ShoE See habe Benen I6 eee 0 ee SHOR RNBSS cele AME cee ame 10:1000 
It will be observed from Table XV that European foulbrood was 
produced in all cases in which larve were fed a suspension of 
Bacillus pluton in sirup medicated with betanaphthol, carboiie acid, 
eucalyptus, formic acid, salicylic acid, salol, and quinin (bisulphate 
of quinin), respectively, in the proportions noted. 
The strongest solutions of the drugs used in the experiments are 
in most instances approximately the maximum proportion of the 
chemical in honey that will be taken by the bees. These prelimi- 
nary results indicate that drugs should not be depended upon, for 
the present at least, in the treatment of European foulbrood, and 
emphasize the fact that beekeepers should make sure that the value 
of a drug has been demonstrated fully before it is used. 
TRANSMISSION OF EUROPEAN FOULBROOD 
While there is yet much to be learned concerning the transmission 
of European foulbrood, the data at hand relative to this important 
phase in the study of the disease justify certain statements in regard 
to it. The disease can be produced experimentally by feeding a 
healthy colony the crushed larvee sick or dead of the disease, sug- 
gesting that infection takes place by way of the alimentary tract. 
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