28 



Livingston : Chemical stimulation of a green alga 



Tari.e of certain results obtained I5V Stevens : lowest inhibiting 



» 





CONCENTRATION 





_ j-y 



Salt, Boirytis. 



Macrosporluw, 



Gloeosporiunt. 



Penicillium. 



Uromyces. 



IlCl 





;> znfioo 



]> ?ij 100 



w/6,400 

 75«/ 100,000 



> w/3,200 



>I5;// 10,000 



'y-m/lOO 



> w/ioo 



> m/ioo 



' >S«/i,ooo 



1 



1 



>w/S0 



> 2«/lOO 



>w/So 



>;//ioo 



;^i / 200 

 25;// 10,000 



f?ij 200 

 25«/l0,000 



m]2 

 5«/io 



> w/io 

 >5-'//ioo 



w/50 







znfioo 

 mfso 



CuSO^ 

 Cu(N03), 



ff//3,200 



i5«/io,ooo 



w/3,200 

 15;// 10,000 



w/2 



5;// 10 



> njioo 



PZJ'^,20Q 



iS«/ 10,000 



/;//3,200 



i5«/io,ooo 



ffljZ 





1"" 



MgSO, 





1 



5«/io 











Clark * worked in a field similar to that of Stevens, making 

 valuable determinations of the effect of poisons upon fungus growth 

 as well as upon the germination of spores. Below are presented 

 those of his results which are of most interest in the present con- 

 nection. The figures denote the lowest fatal strength for the 

 organisms indicated. I have added the decimal equivalent as 

 above, placing it to the right of the sign 

 the salts in the order of their toxicity. 



and have arranged 



Table of certain results obtained by Clark 



Aspergillus, 



Salt. 



Fatal concentration 



SierigJimfocystis. 



CoSO^ 



HCl 



CuSO^ 



Cu(NO,), 



H N O3 



ca(NO,), 



AgNO, 



7;/4 

 ;//4 



«/4 



«/64 

 ;//2,048 



n = n 



25;//! 00 



25«/lOO 

 25«/lOO 



1 25;//!, 000 



625;//l0,000 



i56«/io,ooo 

 49^/100,000 



Fatal concentration, 



CoSO 



ZnSO^ 



HCl 



HKO3 



Ni(N0.;)2 



Cu{Nqo, 



CuSO^ 



H,SO, 



Cd(N03), 



AgNO^ 



n 



n 



n 



n\2 

 «/4 

 w/4 



«/4 



n 



25 ;// 1 00 

 25^/100 



ZpljlOO 



njS^z 125^/1,000 



«/l6 =:: 625«/l0,OOO 



w/32 = 313^/10,000 

 3?//4,o96 — 245/1,000,000 



Peniciliiittn. 



Salt. 



CoSO^ 

 CuSO^ 



Cu(N03), 

 ZnSO. 



HCl 



Fatal concentration 



Penicillhifn. 



\\ 



Fatal concentration 



«/2r^5«/lO 



k/2 := 5;z/io 

 fi/4:^2^nhoo 



«/256 



'^ / 32, 76S :^ 305 «/ 10,000,000 



39«/io 000 



♦Clark, }. F. On the toxic effect of deleterious agents 'on the germination and 

 development of certain filamentous fungi. Bot. Gaz. 28 : 289-327, 378-404. 1899. 

 — Electrolytic dissociation and toxic efFect. Jour. Phys. Chem. 3: 263-316. 1899. 



