1893. EXPERIMENTS ON LIVING CELLS. 430 
dextrin, albumen, glue, were also successfully employed as neutrali- 
sing agents ; while sugar and salt, which dissolved in the water, were 
almost wholly ineffective. 
Results were for a time much confused by the persistence of 
after-effects in the vessels. The glasses in which coins had been 
immersed retained, to some degree, oligodynamic power, even after 
careful cleansing, and the effect continued, all unknown to the 
experimenters, during three or four subsequent cultures. 
Nageli had now arrived at what seemed to be a deadlock ; that 
almost insoluble substances should exert ‘so fatal a power, and that 
quite insoluble substances should be effective in counteracting it, was 
very mysterious. 
Would electricity, or some such imponderable agent, he asked, 
account for the facts? And so there were started new experiments 
to put this theory ‘to the test. 
The first bore upon Temperature; but here again he was 
baffled, as neither excessive heat nor sudden change accounted for 
the hidden force. 
The effect of Light was questioned, and that also gave no response. 
There remained Electricity. Had it been generated in the water 
by the metals employed, and did Sprrogyra cells act as an electroscope, 
exceeding anything hitherto known in sensitiveness? This theory 
also was found untenable. Vessels of water were separately charged 
with positive and negative electricity, and the plants were put in. 
They remained unaffected, and equally so when a strong induction 
current of electricity was passed through a tube in which filaments 
had been placed. The plants were further exposed to the direct action 
of electricity from a battery; this caused the cells to swell, and 
induced other changes, but it in nowise resembled the action of 
ohgodynamics. 
The only conclusion left was that here was a new power not to 
be accounted for by any present theories ; either a new agent was at 
work, or the old agents had developed new properties. 
The problem was attacked again, to see if the metals above- 
mentioned acted in solution or in mass. ‘Gold and platinum are 
quite insoluble ; they had already been tested, but the gold coins used 
were alloyed with copper. Pure gold was prepared from gold 
chloride, and the platinum was treated with hydrochloric acid; they 
were then found to be harmless, and also it was now proved that 
washing with acid would neutralise oligodynamic glasses. Thus it 
was, in all probability, some barely soluble substance, such as copper, 
that had to be dealt with. 
Oligodynamic water was analysed, and was found to contain 
lead, zinc, copper, and iron. Some copper coins were left for a 
stated time in water till it became strongly oligodynamic. On 
analysis, the solution yielded one volume of copper to seventy-seven 
million volumes of water. 
