272 Early Studies in Bacterial Plant Diseases 



That same evening, before the Botanical Seminar meeting, 

 Smith presented his first technical description of the organism in 

 a twenty-minute address, entitled, " Bacillus tracheiphilus, new 

 species, the cause of blight in cucurbits." April 30, 1895, Central- 

 hlatt jiir Bakteriologie published his first real pronouncement in 

 plant bacteriology,, " Bacillus tracheiphilus sp. nov., die Ursache 

 des Verwelkens verschiedener Cucurbitaceen." " 



This was published in the second, or Zweite, Abteilung. General 

 medical bacteriology had been given the first, or Erste, Abteilung 

 of the Centralblatt. Publications on diseases of plants, along with 

 those on bacteriology of the soil, . dung, milk, cheese, vine, and 

 chemical technology, were now, so far as this publication was 

 concerned, officially in separate status. Throughout the first 

 twenty-five volumes of the section devoted to plant bacteriology. 

 Smith was to serve as an associate editor of the journal. He had 

 not finished with the researches on Bacillus tracheiphilus. Years 

 later, he would devote the first of several chapters on specific 

 bacterial plant diseases in his famous text, Introduction to Bac- 

 terial Diseases of Plantsl^" to the cucurbit wilt. In the second 

 volume of his monumental three-volume work, Bacteria in Rela- 

 tion to Plant Diseases,'^ ninety pages were to be given over to a 

 consideration of the wilt of cucurbits. Furthermore, numerous 

 references and descriptions of the disease were to appear in other 

 less important articles and treatises. 



In his investigation of the cucurbit wilt and the next plant 

 bacterial disease which he studied, that of tomato, tgg plant, and 

 Irish potato caused by Bacillus solanacearum new species, Smith 

 achieved several important extensions of laboratory technique. 



After Smith had sufficiently completed his inoculation experi- 

 ments of pure cultures of Bacillus tracheiphilus in acidified and 

 alkaline broths to be satisfied with his conclusion that the germ 

 is sensitive to acid tissues of the plant and thrives on alkaline 

 juices, on January 5, 1895, he took potato broths mixed with 

 organic acids — malic, succinic, citric, tartaric, and oxalic — in pro- 

 portion of lOcc. broth to Ice. N/lO acid, which gave, he noted 

 in his memoranda, about the same acidity as unboiled juice of 

 the cucumber plant. These were steamed and sterilized, and a 

 precipitate formed in the oxalic filtered out. The results of these 



"2(1): 364-373, 1895. ''-Op. cit., 132-145. " O/'. cit., 2: 209-299. 



