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Walter Stiles 
sodium chloride in which deplasmolysis just took place after various 
times of immersion. It was found that after immersion for five 
minutes in o-oi N oxalic acid or 0-005 N hydrochloric acid the 
plasmolysing concentration of sodium chloride rose more rapidly 
than after a preliminary immersion for five minutes in tap water. 
The rise in the value of the limiting plasmolysing concentration is 
attributed to the absorption of sodium chloride and hence it is con¬ 
cluded that dilute acid has the effect of increasing the permeability 
of the cells in question to sodium chloride. 
The observation of Puriewitsch (1898) that exosmosis of sugars 
or other soluble food reserve substances from storage tissue is in¬ 
hibited in absence of oxygen or in presence of anaesthetics, is regarded 
by Livingston (1903) as probably a case of the influence of a dissolved 
substance on the permeability of a cell membrane. Yet to me 
Puriewitsch’s original explanation, namely, that the absence of oxygen 
or the presence of anaesthetics influences the enzymes present so 
that the stored food material is not converted by enzyme action into 
a diffusible form, appears at least as probable. Livingston finds it 
difficult to understand how enzyme action could enter into the 
question in cases where the food reserve is in a soluble form as in the 
case of sugar in onion and beet root. It might, however, be the case 
that there is here a transformation of disaccharides or more complex 
sugars into the more easily diffusible hexoses or pentoses. 
The influence of various narcotics on the absorption of salts by 
leaf cells was examined by Trondle (1920) by the plasmolytic method 
used by him to test the action of acids on permeability. Assuming 
the legitimacy of the method, which is in' doubt, it was found that 
previous immersion for 20 minutes in 0-5 per cent, chloral hydrate 
reduced the rate of absorption of sodium chloride by leaf cells of 
Buxus sempervirens, while immersion of the same cells for the same 
time in 1 per cent, chloral hydrate or 3 per cent, (by volume) ether 
at about 15 0 C. completely inhibited the intake of salt. The absorption 
of potassium chloride by leaf cells of Acer platanoides was inhibited 
by previous immersion for 15 minutes at about 21 0 C. in 1 per cent, 
chloral hydrate, and similarly the absorption of sodium nitrate by 
leaf cells of Lupinus alhus was inhibited by immersion for 20 minutes 
in the same solution. From these results Trondle concludes that 
narcotics reduce the permeability of cells to salts, even to complete 
impermeability. 
