THE ACTIVE FORCES OF LIVING ORGANISMS 19 



steadily diminishes. These considerations do not, it 

 is true, go to the root of the matter, for no definite 

 statement can be made until the conditions under 

 which the red corpuscles are manufactured are more 

 clearly known. 



The analysis of the substance of the nuclei of cells Nuciein, 

 by various observers shows that nuclein, its chief and ^^°" 

 ingredient, contains the elements carbon, hydrogen, ''^ ™' 

 nitrogen, phosphorus, and oxygen. The results ob- 

 tained on different occasions do not, unfortunately, 

 allow the proportion in which they occur to be fixed 

 with absolute certainty, but the following formula* 

 may be taken as showing approximately the amount 

 of each : Co9H49N9P3022. 



It is interesting to compare this formula with those 

 of two of the chief constituents of the brain,! viz., 

 protagon (CjeoHgjgNjPOss) and lecithin (C44H9„NP09). 

 In the first place, we see that, though these three 

 substances are built up on somewhat similar lines, 

 since they each contain nearly twice as much hydro- 

 gen^ as carbon, and small amounts of nitrogen and 

 phosphorus, yet nuclein contains a relatively con- 

 siderable amount of oxygen. This fact points to the 

 conclusion that the amount of oxygen present, or, at 

 any rate, the degree of oxidation going on during its 

 formation, is greater than is the case when in their 

 respective localities of origin protagon and lecithin 

 are formed. Lecithin, it is true, is a substance which 



* Foster's ' Physiology,' Appendix, Sheridan Lea, p. 88. 

 t Ibid., pp. 134-187. 



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