Duggar — Relation of Marine Algae to Salt Solutions. 481 



erul table given below. In every case the control algae re- 

 mained healthy. 



In Table IV there will be found a tabulation similar to 

 the preceding, for the work done at Cette. In both tables 

 given, the substances are arranged in groups of the metal 

 radical, and it will be seen at a glance that there is more or 

 less irreguhirity in the toxic strengths indicated, from the 



Table III. 



Table IV. 



Sub.stance 



NH4CI 



NH^NOs. .. 



(NH4)2S04. 



CH(NH3)0 



KBr.... 

 KCl . . . . 



KNO3 . . 

 K2SO4 . 

 CHKUa 



NaBr • , . 

 NaCI .... 

 NaNos . . 

 CHNa02 



CaCl2 .... 



Ca(N08)2. 



% N (perinit- 

 tiug health) 



Substance 



. .0058 

 . .0059 

 . .005 

 — .01 



NH4Br ., 

 NH/n . 

 NH4NOS 



. .037 

 . .093 

 . .073 

 . .08 

 .—.017 



KI .... 

 KBr... 



KCl . 

 KNO3 • 

 K2SO4 • 



.133 

 .13 

 .093 

 .047 



Nal.... 

 NaBr... 



NaCl... 

 NaNOs . 

 Na2SU4. 



MgBrj 



MgCl2.... 

 MgCN0s)2. 

 MgS 4 ... 



.13 

 .12 



Car2 



CaBr2 . . . . 



CaCl2 



Ca(N03)2 



.193 



.24 

 .27 

 .37 



M£l2 



Mi:Br-2 



MgCli.... 

 Mg(N03)2. 

 MgS04... 



7o N (pernait- 

 tiug health) 



.001 



.0025 



.0025 



.02 



.056 

 .081 

 .087 

 .lO(-) 



. .03 

 . .104 

 .+.275 

 . .205 

 . .2875 



.11 

 .25 



.25-. 30 

 .19 



. .008 

 + .30 

 . .S4 

 . .225 

 . .40 



iodide or the bromide of the particular metal to the sulphate. 

 Between the different metals there is great diversity of effect, 

 ammonium compounds, for instance, being strongly toxic, 

 whereas the magnesium compounds are almost inert in this 

 regard. When nutient salts alone are considered, there is, 

 moreover, no great diiference between the strengths, as a rule, 

 of compounds of the same metal, yet further results may in- 



