1914] HOYT—COLLOIDAL METALS ars 
which became deeply stained by the metal. This swelling was 
especially pronounced when the filaments were transferred from the 
alkaline colloidal gold or platinum solution to non-toxic distilled 
water. The swollen masses thus produced often parted from the 
rest of the wall, leaving the latter uncolored and apparently 
unaffected. 
6. The cell walls were apparently unaffected by colloidal silver, 
either alone or with NaOH, or with salts to form a 0.5 per cent 
Crone’s solution. They seemed to be unaffected by colloidal 
platinum alone or by a mixture of this with colloidal silver. Only 
very slight swelling of the walls occurred in solutions of NaOH 
alone. Marked swelling occurred only with the solution of colloidal 
gold or of colloidal platinum in the presence of NaOH. A solution 
of AuCl, and NaOH was without effect in this regard. 
7. Filaments of Spirogyra originally from the same culture, but 
grown for a time in different media, exhibited different reactions in 
the solutions of colloidal gold and NaOH, as well as in the other 
toxic solutions here employed. 
Jouns Hopkins University 
BaLtrmmore, Mp. 
LITERATURE CITED 
1. BREAZEALE, J. F., Effect of dae agi upon the growth of seedlings in 
water cultures. Bor. Gaz 
2. Brepic, G., Darstellung colisidaier Meu sungen durch elektrische 
_Ferstiubung Zeitschr. Angew. Chemie 1898: 951-9 : 
» Einige Anwendungen des elektrischen igceibegen Zeitschr. 
Basse sess 18 
= os eau ppemees Piciente. Leipzig. 1 
6. GaLeortt, G., Uber die Wirkung ‘ollaidaler ead elektrolytisch dissozierter 
Metall-lésungen auf die Zellen. Biol. Centralbl. 21:321-329. 1901. 
7. HatcHer , R. A., The effect of colloids in diminishing the toxicity of 
strychnine. Amer Jour. Pharm. 74:283-285. 1902. 
8. Hoyt, W. D., Some toxic and antitoxic effects in cultures of Spiroygra. 
Bull. Torr, Bot. Club 40:333-360. 19 
9- JENSEN, G. H., Toxic limits and icles effects of some salts and 
Poisons on eheat. Bor. Gaz. 43:11-44. 1907. 
