Duggar — Relation of Marine Algae to Salt Solutions. 481 



eral 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 irregularity in the toxic strengths indicated, from the 



Tablk III. 



Tablk IV. 



Sobstaoce 



NHiCl 



NH^NOs 



(NH4)3S04. . 

 CH(MH3)02- 



KBr.... 

 KCl . . . . 

 KNOs.. 

 K2SO4 . . 

 CHKOs 



NaBr 133 



NaCI 13 



NaNos 093 



CHNaOa 047 



% N (permit- 

 ting health) 



Sabstance 



. .0058 

 . .0059 

 . .005 

 — .01 



NH^Br .. 

 NH^Ol . 

 NH4NOS 



. .037 

 . .093 

 . .073 

 . .08 

 .—.017 



KI ... 

 KBr.. 



KCl 



KNO3 



K2SO4 



CaClj 



Ca(N08;,. 



MgBr, . . . . 

 MgCh... 



MgCN08)8. 

 MgS 4... 



Nal.... 

 NaBr... 



NaCl... 

 NaNOs • 



.13 

 .12 



Cal, 



CaBra 



CaCl2 



Ca(N03)2 



.193 

 .24 

 .27 

 .37 



Mslj 



M-Br2 



MgCli.... 

 Mg(N08)8- 

 MgSOi... 



% N (permit- 

 tiug health) 



.001 



.0026 



.0025 



.02 



.056 



.081 



.087 



.lO(-) 



. .03 

 . .104 

 .+.275 

 . .205 

 . .2875 



.11 

 .25 



.25—30 

 .19 



. .008 

 +.30 

 . .S4 

 . .226 

 . .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 difference between the strengths, as a rule, 

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



