113 



Acid J^'uchsin Test. 



The action of Ps. hyacinthi on acid fuciisin was tested in peptone 

 water. The culture medium was prepared as follows: 



200 c. c. distilled water. 



2 gm. Witte's ijeptonum siceuiu. 



4 c. c. acid fuchsin water. 



2N 

 10 drops Y" l^^l {^^ counteract the alkalinity of the i.c[)tone). 



The acid fuchsin water consisted of 150 mg. of Griibler's Fuchsin 

 S. (aft(u- Weigert) dissolved in 30 c. c. of distilled water. 



The tubes each contained 10 c. c. of the rose-red fluid. They were 

 inoculated on March 21. Tubes 1, 2, and 3 Avere inoculated from fluid 

 cultures; tubes 1', 2', and 3' were inoculated from solid cultures. The 

 residts ol^tained Avith Ph. hyacinthi (tubes 1 and 1'), Pa. ccmijjeHtris 

 (tul)es 2 and 2'), Ps. stewartl (tubes 3 and 3'), B. j)yoc. pericarditidis 

 (tu])e 4), B. coli (tube 5), B. araylovo'rus (tube 6), and B. carotovoras 

 (tubes T to 10) are summarized below: 



MarcJi 24. — Slight variations in color, but each tube paler than the check tubes. 



March 21. — Nos. V ^ 2, 2^, 3^, 4, and 5 are much alike in color. They have faded 

 considerably; i. e., they are now rose color. Nos. 1, 3, and 6 are deeper red. None 

 are colorless, but all except 7-10 are paler than on the twenty-fourth. 



March 30. — There has been a marked loss of color in 1, V, 2, 2^, 4, and 5, and the 

 fluids in these tubes are now only pale pink. In 3, 3^ and 6 there has been only a 

 moderate fading. 



Aprils. — Aljout one-tenth of the color is left in 1 and V] i.e., 1 c. c. of the red 

 fluid from a check tube diluted with 9 c. c. of water gives a color a trifle deeper than 

 that in these tubes. Only one-twelfth to one-fifteenth of the color remains in 2 and 

 2\ In 3 about one-fifth of the color remains, in 3^ about one-eighth, in 4 about 

 one-tenth, in 5 about one-ninth, in 6 about one-seventh. In 7-10 there is no fading. 



xipr'd ii,— The cultures still fall into three groups, i.e.: (a) Those in which nearly 

 all of the color has disappeared, viz, Ps. hyacinthi, Ps. campestris, and B. jjyoc. pcri- 

 carcfitidls. (b) Those in which a considerable portion of the color remains, viz, Ps. 

 slewarti, B. coli, and B. amylovorus. (c) Those in which the color remains the same 

 deep red as on the start, viz, Bacillus carotovorvs. 



April 18. — About one-tweniieth of the color is left in 1 and V\ precipitate yellow. 

 Only about one-fortieth of the color remains in 2 and 2' . In 3 there is about 5 times 

 as much color as in 1 and V\ in 3^ about twice as much. The color in the latter tube 

 is Bidgway's rose pink. The ])recipitate in 3 and W is yellow; it is most abundant 

 in 3^. No. 4 is like 1 and V \ ])recipitate white. In 5 and 6 the color is rose pink; 

 precipitate white, more copious in 5 than in 6. In 7-10 a slight whHe precipitate 

 and no change in color. 



April 29. — Color gone in 1 and V. On looking through the fluid endwise there is 

 a trace of vinaceous buff, but held up vertically to the light (16 nun. diameter) it 

 appears colorless. Nos. 2, 2^, and 4 are like 1 and V , and there is no change in 7-10, 

 i. e., it is as red as on the start. The rest of the tubes (3, 3^, 5, and 6) still show 

 some color. 



May 16. — Color has not entirely disappeared from 3, 3^, 5, and (i. The color in the 

 4 tubes of B. carotovorus is now only one-half as deep as it was on April 29. The 

 rest are still colorless. 



21788— No. 28—01 8 



