Igo] LIPMAN—SOLUTIONS FOR BACTERIA 211 
various combinations of four salts each, and for comparison with 
them solution 3 of table II containing three salts and solution 6 of 
table IT containing only two salts. 
From table III it is plain that the various combinations of four 
salts, though allowing a fairly good production of ammonia, are not 
as favorable to B. subtilis as either 5 or 6, which contain respectively 
only three and two salts. It appears evident that the combinations 
of four salts there employed have not the favorable composition of a 
balanced solution, and since it could not easily be ascertained as to 
what was the depressing agent in these solutions, it was decided 
to run another series with different combinations of four salts each, to 
See if any other combination of four salts can more nearly be made to 
approach the balanced solution. 
SERIES IV 
Since calcium proved to be so toxic a salt to B. subtilis,+ it was 
thought that an improvement could be made in the combinations of 
four salts by using smaller amounts of calcium than were employed in 
the last series, and solutions of four salts each (shown in table IV) 
TABLE IV 
ALL QUANTITIES GIVEN REFER TO CUBIC CENTIMETERS OF 0.35 % SOLUTIONS 
PEPTONE CONTENT 0.91 PER CENT. 
Number Culture solutions . past ee 
too NaCl 
25 KCI 
ee a 10 MgCl, 20.70 
2 CaCl, 
100 NaCl 
25 KC} 
REGAN et 10 MgCl, 21.12 
+ Cacl. 
100 NaCl 
1o KCl 
Re a ay 10 MgCl, 28.42 
cach, 
100 NaCl ; 
ee rR pha to MgCl, 25.88 
* acl 
ide ee ue Peptone in mma _ 42.5% 
ee ae ants Peptone in tap wa af 9° 
* Lipman, Cuas. B., Bor. Gazette 48: 105-125. 1909. 
