534 
Williams.—-Absorption of Gold by Fungi . 
The only evidence at present in support of the second suggestion is 
the final alkalinity of the tannic acid preparations after all the gold has been 
removed by the fungus. 
Summary. 
1. Conidia of Penicillium glaucum and Oidium lactis can develop in 
colloidal gold solutions which contain tannin or gum arabic. 
2. The living fungus, during growth, removes the metal from the solu¬ 
tion. Retention occurs in such walls as are not cuticularized. 
3. The process goes on more irregularly when masses of dead fungus 
are introduced into solutions. 
4. Solutions with a higher rate of diffusion colour the fungus more 
quickly than those with a lower rate. 
In all cases the accumulation of gold finally produces a blue coloration. 
5. No explanation of the process can be given. 
In conclusion the writer wishes to express her best thanks to Mr. Hat- 
schek and Dr. Willows for many suggestions with regard to the physical 
preparations and determinations, and to Mr. H. B. Lacey for much help in 
the botanical matters. 
The Sir John Cass Institute. 
Bibliography. 
1 . Hatschek, E. : Introduction to Chemistry and Physics of Colloids, p. 8. 1913. 
2 . Svedberg, The. : Die Methoden zur Herstellung kolloider Losungen, p. 73. 
3 . Freundlich: Kapillar-Chemie, p. 364. 
4 . Ostwald : Grundriss der Kolloid-Chemie, p. 269. 
