ON ENZYMES AND LIVING CELLS 211 



normal 1 increased markedly the growth even in the earlier 

 stages, and not merely after one or two days, as Loeb had previously 

 found, while the addition of half as much more sodium hydrate practic- 

 ally stopped the growth altogether, the cells not proceeding beyond 

 the four-cell stage. Addition of double the quantity, ^ normal, 

 stopped the growth entirely. Addition of hydrochloric acid slowed 

 the growth from the beginning, and at 5-^ normal the growth 

 was stopped entirely, all the cells remaining in the single-cell stage. 



The action of alkaline and acid salts, such as the phosphates 

 and carbonates, corresponding to their lessened concentration in 

 hydroxyl or hydrogen ions, was less effective, and these salts had 

 to be added in greater concentration. 



In addition to the alteration in rate of growth, it was found 

 that the addition of alkali, in more than the minimal concentra- 

 tion of T oVo normal, led to marked irregularity in the size and 

 shape of the cell, and to irregular nuclear division. In the large 

 undivided cells, multiple nuclei were found, and many division 

 figures were seen with the chromatin reduced in quantity, and 

 in number of chromosomes. In many cases division with three 

 and four centrosomes was observed. 



In the cells to which acid has been added, no such increase 

 in nuclei was observed, nor nuclear division figures, and in many 

 cases the chromatin appeared to have been acted upon chemically 

 and to have disappeared. 



The experiments illustrate the extreme sensitiveness of the 

 living cell to variations in concentration of the hydroxyl and 

 hydrogen ion, and the importance of a normal reaction of the 

 medium for cell growth and division. 



ACTION OF ANTISEPTICS AND PROTOPLASMIC POISONS. 



There is here a great quantitative difference in action upon 

 enzyme and living cell respectively, which probably has for its cause 

 the more complex and highly organised chemical structure of the cell, 

 causing it to enter more readily into combination with the antiseptic. 

 That the difference is a quantitative and not a qualitative one, how- 

 ever, is shown clearly by many experiments which go to prove 



N 

 1 That is, 1 c.c. of =-^ alkali per 100 c.c. of sea water: this amounts to 



only 1 part by weight of sodium hydrate in 25,000 parts by volume of sea 

 water. 



