

THE REACTION OF PLANT PROTOPLASM 



x\, R. Haas 



most im 



metabolism. It is not, however, the apparent reaction (or total 



im 



the actual reaction, as shown by the gas chain or by indicators. 

 The total acidity includes both undissociated and dissociated acid, 

 while the actual reaction depends only upon the latter. 



In the case of a buffer solution 1 the total acidity may be very 

 high, while the actual acidity may be very low. The higher the 

 total acidity in this case the more difficult it becomes to change 

 the actual reaction by the addition of acid or alkali. This applies 

 to protoplasm, w r hich always has the properties of a buffer solution 

 (since it contains carbonates, phosphates, proteins, etc.). Hence 



asm 



may 



actual acidity. 



So far as the writer is aware, no determinations of the actual 

 reaction of plant protoplasm have been made by means of the gas 

 chain (except a single determination of pineapple juice made by 

 Reed 2 ). Only a few determinations have ever been made 3 



means of indicators. 



6 



number 



some 



their unusual acidity. 



cms 



determine the acidity of the iuice bv means 



The gas chain used was essentially the form described by 



HlLDEBRAND 



Chemie 



Berlin. 19 14. 



2 Unpublished results. 



* Cf. Friedenthal, H., Zeit. Ailg. Physiol. 1 .-56. 1902. It is not known whether 

 in these experiments the proper precautions were taken to crush all the cells and to 



secure plant juices which had as high an acidity as the cell contents. 



4 Hildebraxd, J. H., Jour. Amer. Chem. Soc. 35:869. 1913. 



Botanical Gazette, vol. 63] * [232 



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