113 



Acid Fuchsix Test. 



The action of Ps. hyachithi on acid fuchsin was tested in peptone 

 water. The culture medium was prepared as follows: 



200 c. f. distilled water. 



2 gm. Witte's peptonum siccum. 



4 c. c. aeid fuchsin water. 



2N 

 10 drops -, HCl (to counteract the alkalinity of the peptone). 



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

 S. (after Weigert) dissolved in 30 c. c. of distilled water. 



The tubes each contained 10 c. c, of the rose-red fluid. The}^ were 

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

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

 results obtained with Ps. hyacinthi (tubes 1 and 1'), Ps. canipestris 

 (tubes 2 and 2'), Ps. stmnarti (tubes 3 and 3'), B. j^yoc. perlcarditidis 

 (tube 1), B. coll (tube 5), B. amylowms (tube 6), and B. carotovorus 

 (tubes T to 10) are summarized below: 



March 24- — Slight variations in color, l)ut each tube paler than the check tubes. 



March -27. — Nos. 1', 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, 1^, 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. — About 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. 



April 11. — The cultures still fall into three groups, i. e. : (a) Those in which nearly 

 all of the color has disappeared, viz, P.s. hyacinthi, Ps. campcstri.'^, and B. pi/oc. peri- 

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

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

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



April 18. — About one-twentieth of the color is left in 1 and V; i)recipitate yellow. 

 Only aljout one-fortieth of the colcn- remains in 2 and 2'. In 3 there is a})out 5 times 

 a.s much color as in 1 and F; in ?/ about twice as much. The color in the latter tube 

 is Ridgway's rose pink. The precipitate in 3 and 3^ is yellow; it is most abundant 

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

 precii)itate white, more copious in 5 than in 6. In 7-10 a slight wh^'te precipitate 

 and no change in color. 



April 2!). — Color gone in 1 and V. On looking through the fluid endwise there is 

 a trace of vinaceous buff, but held uyi vertically to the light (Ifi mm. 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 iias not entirely disapi)eared from 3, '.V, 5, and 6. The color in the 

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

 vest are still colorless. 



21788— No. 28—01 8 



