Igt0] LIPMAN—SOLUTIONS FOR BACTERIA 213 
centration of 0.53 m with an alkaline reaction. ‘The dilute sea - 
water was made by adding distilled water to the concentrated sea 
water until a concentration of 0.35 m (or that used in all the other 
solutions) was obtained. The artificial sea water is VAN’t Horr’s 
solution and is neutral in reaction, thus according with the reaction 
of all other solutions employed. 
The superiority of the sea water solutions whose concentration 
does not exceed 0.35 m can be easily seen from table V. It is plain 
that the artificial sea water and the natural sea water of the same 
concentration are by far the most superior of any salt mixtures tried, 
and though in the last table it is compared with the most favorable 
salt mixtures and those which appear to approach most closely to a 
balanced solution, it excels even those to quite a marked extent. 
Rincer’s solution, not having the magnesium salt which seems to 
act so beneficially in balancing solutions for B. subtilis, gives only a 
fair ammonification coefficient as compared with other salt mixtures. 
SERIES VI 
It seemed of interest to see what effect the addition of magnesium 
to the RINGER’s solution would have, and a series was therefore 
arranged to show this. 
TABLE VI 
ALL QUANTITIES sagen! REFER TO CUBIC gianguianagg ional OF 0.35 m SOLUTIONS 
EPTONE CONTENT 0.9I PER C 
Number Culture solution ee ee 
Pe cena RINGER’Ss solution 19.74 
RINGER’S solution 
Por pak 26. 
+10 MgCl, Mee 
5 RE ree Artificial sea water 31-41 
Ee eee Peptone in brook water 39-89 
Se aa Peptone in distilled water 42.51 
too NaCl 
Sa 10 MgCl, 28.42 
eae 1o KCl . 
2 CaCl, 
It is quite evident that the addition of magnesium to RINGER’s 
- Solution has a very favorable effect, and by slightly changing the 
Proportion of the constituents we could easily obtain what appears 
