1911.] Radium Radiations upon Normal Blood. 



125 



by the following experiment, which is typical of several : — A glass bulb of 

 volume 30 c.c. contained 2 c.c. of citrated blood and emanation equal in 

 quantity to the equilibrium value of 26'5 mgrm. EaBr 2 . The blood was 

 examined at different times and a count made, by means of a Tboma Zeiss 

 apparatus, of the percentage of completely haemolysed corpuscles. The 

 results are indicated in Table I. 



Table I. 



Time of exposur 



1 Completely hsemolysed corpuscles. 

 Percentages. 



hours. 

 2 





6 



1 



19 



7-2 



42f 



84 



When haemolysis was complete, the corpuscles were found to be colourless 

 and slightly shrunk, but retaining their corpuscular form. The spectrum of 

 met-haemoglobin was observed at the end of the observations. The con- 

 version from oxy-haemoglobin was not complete, however, as some of the 

 bands of this substance were also visible.* 



The haemolysis was found to be due to a direct action of the a-particles on 

 the red corpuscles by the following experiments : — 



(1) Emanation mixed with washed red corpuscles gave marked haemolysis 

 in 24 hours. 



(2) Emanation mixed with serum for 24 hours and the latter added to 

 washed red corpuscles gave no haemolysis. 



(3) Emanation enclosed in a glass tube just thick enough to exclude the 

 a-rays, while allowing free exit of the /S- and 7-radiations, produced no 

 haemolysis in blood contained in a tube which surrounded that in which the 

 emanation was held. 



The concentration of the emanation in these three experiments was nearly 

 the same as in that initially described. The direct proof of the haemolysis 

 being due to the a-particles has been shown by means of the apparatus 

 of fig. 1. 



A finely powdered specimen of radium bromide was spread over a circular 

 area of 2 sq. cm., this being the bottom of a cavity 1 mm. deep in a 



* Haemolysis and the formation of met-haemoglobia have been observed by Henri and 

 Mayer (' Comptes Eendus,' 1904, p. 521) experimenting with frog's blood and that of the 

 dog, by exposing it to 100 mgrm. of radium. The type of radiation producing the 

 results is, however, not stated. 



