70 



HOPIXESS IX WATTLE BAKK UJPCSIOXS, 



Confirmatory tests were made witli phase Al, a mixture of Al with A2. and 

 with A2 using- levuh)se 2 9c an<i sodium chloride 0.3 '"f . They t)ore out the results 

 obtained witli dextrose and citrate. 



The work has sliown that the jduise A2 can produce ropincss from de.xirnse it 

 glycei'in in. the presence of meat-extract, peptone, asparagin or ammonium sul- 

 phate, and from glycerin with nitrate bnt not from dextrose with nitrate. Doubt- 

 less this is due to the formation of an acid reaction in the mediuui cuntaining 

 sugar and the concomitant jiroductiou of free nitric acid. Ferncyanide produced 

 ropiness, but the (|uantity was scanty as compared with the otlu'r sources of 

 nitrogen . 



The phase B2 acted best witli asparagiu and ammimium sulphate. Meac- 

 extract gave an evanescent ropiness with dextrose, but none at all with glycerin. 

 The behaviour with nitrate was much the same as with A2 and proliidily I'nr the 

 same reason. Ferricyanide was an unsuital)le source of nitrogen. 



'ihe liifluenci of I'oni/d.b- .Vdyar.s,, etc. 



The acti\ity of the bacteria in the presence of various sources of carbon was 

 tested with a saline asparagin solution containing various sugars, etc. liojiiness 

 was jirotluced in the presence of saccharose, dextrose, levulose, galactose, glycerin 

 and mannit. It was not produced from maltose, lactose, dextrin or gum-acacia. 



In testing the most suitable amount of glycerin, a solution ccmtaining 1% 

 sliowed ropiness first, but in time the higher percentages made headway. On the 

 eighth day the order of ropiness seemed to be 5 %, 1 %, 10 % and 2 ' , when tiie 

 slimes were coagulated and weighed. With 1 %, 100 c.c. of media gave 80 milli- 

 gi-ams, 2 % gave 04, 5 '^i gave 88, and 10 % gave 90 inilligrauis. The 2 % te-t 

 was ]irobabIy low, in which case all <|uaiitities gave much tlie same juikiuuI id' fii|)v 

 substance. 



The ropiness seemed to become more ahundiuit when grown in deep layers of 

 fluid; in shallow layers there aiipears In be a greater growth cd' cells ami hss 

 slime. 



An e.xpei'iment was made with carbohydrates when considering the subject 

 of acidity. A solution containing sugar or glycerin 2'~/c. KII.,P(|j 0.2 '^f, 

 MgSO.jAq. 0.1 9r, €a('l20.02% was made nrutrnl to methyl-red and seeded wi; h 

 a mixture of Al +A2 and with B2. 



Talili> xii. Chauge of Kcactiuii with Siigar.« iind (xlvfci-iu. 



