775 



media tbey develop not on tlie snrfjire, but as a (locrulcut deposit in llie liquid. Cer- 

 tain fai-ts uiaj' now be noted aud compared witli tacts aseeitaiued in the curing of 

 to1)acco. 



(1) As tlu; cultures become dry the bactc via cease to develop so rajtidiy, and tinally 

 theii" de\ elopnieut ceases. They reciuire, therefore, moisture for growth, and decreas- 

 ing the amount of moisture decreases their vitality. This l)ear8 out the general view 

 that the origin aud sjtrcad of " pcde burn " is in some way connected with au excess 

 of moisture in the curing barn. 



(2) Nine tul)cs, each containing a slice of sterilized potato, were inoculated with 

 the bacteria. Of these, three were kept at a temperature of 100^ F., three at a tem- 

 ])erature of 70*^ F., and the remaining three at a temi»erature of about 10" F. At the end 

 of 3 days the tubes kept at 70 ' showed the usual growth, the colonies averaging 

 l.f) inches in length by 0.5 incdi in breadth. Neither of the other sets of tubes 

 showed any marked growth, but upon being jdaced at the uu;dium temjierature 

 for 18 hours the dcvelojunont of the baiteria proceeded with marked a(;tivity. 

 These experiments Avere repeated at various degrees of temperature. Tcmi»eraturc, 

 therefore, has a marked intluence upon these germs. Warmth up to 70' aud even 

 DO is favorable to their devcdopmcut, whereas temperatures above 100"^ or 110' aud 

 below 35' to lO"^ act as a temporary or permanent check upon their vitality. To 

 this fact again we find a corresponding theory, that warmth as well as moi.sture is 

 conducive to "pole burn." Inasmuch as in this regard bacteria as a rule follow 

 the laws governing the active growth of the higher fungi, it is imnuiterial at present 

 to decide whether the former or the latter are the primary cause of "pole burn," 

 since the means which may be recommended to prevent the decay apply e«|ually 

 well to arresting or preventing the growth of tho Cladosporium. 



(3) One nu)re fact should b e stated, viz, that all attempts to inoculate thoroughly 

 cured tobacco with the bacteria failed. This result is at least a partial conlirmatiou 

 of the generally expressed view that when tobacco has cured to a certain degree, tho 

 period varying from 10 da»s to 3 weeks after hanging, there is very little danger to 

 be ai)prehended from "pole burn." 



The means for the prevention of "pole burn" and the conditions 

 necessary to the j)roper curinj;^ of tobacco are discnssed. A tobacco 

 bani shonkl be weather-proof and so ventilated that a iree circulation 

 of air can be secured when desired. Attention is called to the fact that 

 the curing- of tobacco is not so much a process of drying" as of fermenta- 

 tion, and that it is therefore desirable to establish conditions which 

 Avill promote tiiose chemical changes which produce the best (juality of 

 cured tobacco. The advantages and disadvantages of curing the 

 leaves on the stalk and of detaching the leaves from the stalk before 

 haiigiug are stated, without a decision in favor of either method. The 

 method for the employment of artiticial heat in curing tobacco, recom- 

 mended in the Report on Tobacco in the Tenth Census of the United 

 States, vol. iii, by J. B. Killcbrcw, is described and the merits of the 

 use of artilicial heat for this purpose are discussed. "To aid the 

 l)rocess of fermentation when other conditions are unfavorable and to 

 establish within the barn at critical periods conditions which shall 

 l)rcvent the occurrence of ' itolc-burn,' are the only uses for artificial 

 heat in this connection." 



Stem kot of tobacco, W. C. Sttjegis, Ph. D. (pp. 184-186). — A 

 popular description is given of Bolryiis loiufihraclilnlaj the fungus caus- 

 ing the stem rot which often injures tobacco in the later stages of cur- 

 ing. The thorough cleansing of the curing barn aud the destruction of 



