506 Scientific Proceedings, Royal Dublin Society. 



by Loeb in 1898, and using similar methods, Moore, Roaf, and Whitley 

 have found by direct observations on the embryonic cells of Echinus 

 that even small increase in the concentration of the negative ion (HO) will 

 accelerate growtli,' But if the alkalinity be increased yet a little, pathological 

 mitoses make their appearance, and at a slightly greater alkalinity the 

 chemical actions necessary for the life and metabolism of the cell are inhibited. 

 On the other hand, an increased concentration of the positive ion (H) from 

 the first retards, and, if pushed further, inliibits growth. The parallel with 

 the action of alkaline sensitizers and acid retarders upon the film is obvious. 



In the light of the observations of Moore, Eoaf, and Whitley we can even 

 offer a probable explanation of the effects of radiation on the cell which is 

 not, fundamentally, unlike that which we have advanced for the formation 

 of the latent image. The electronic discharge in the cell is — as we have 

 seen above — very great. Part of this is directly imported from without (the 

 radioactive supply of /3 rays), and part is derived from atoms within 

 the cell. The first all goes to the increase of the coucentration of negative 

 ions within the cell, The latter may also do so in effect, in so far as it is 

 derived from the less chemically important elements present. The already 

 existing positive ion, as in the case of the silver ion of the film, will not readily 

 part with an electron, but the tendency is for it to be freed from its valency 

 ties or actually neutralized. Thus the negative ion which accelerates mitosis 

 is increased in concentration, and the positive ion wliieh acts to retard it is 

 eliminated. Chemically, the effect is to increase the alkalinity, and all the 

 sequence of events observed by Messrs. Moore, Roaf, and Whitley takes place 

 as the dosage is increased. 



Observations showing an abnormal lowering of acidity in the digestive 

 secretions of cancerous patients have been made by several investigators. 

 Messrs. Moore, Eoaf, and Whitley in 1905 found that the diminution of 

 hydrochloric acid in tlie stomach was independent of the location of the 

 disease." Copeman and Hake, in 1908, published results which failed to 

 confirm those of Moore.^ The question as regards the secretion of HOI cannot 

 be regarded as finally settled. But a lowering of acidity as a frequent feature 

 in cases of malignant disease seems to be accepted as proved. Witli old age 

 a similar phenomenon is observed, and with advancing years the liability to 

 cancer increases. 



' Moore, Roaf, and Whitley : Pi-oc. Roy. See, Ser. B, vol. Ixxvii, Oct., 1905. 

 = Moore, Eoaf, and Whitley : Proc. Roy. Soc, Ser. B, vol. Ixxvii, May, 1905. 

 ^ Copeman and Hake : Proc. Roy. Soc, Ser. B, vol. Ixxx, June, 1908. 



