48 A FKW CHEMICAL CHANCJES. 



tiuii Wii.-^ Kiilv at rile surt'ac;' next tlic air. for on scraitiii<i- the 

 surface of the rml wirli a knife, \\\v iiisiiU' was found to lunc 

 tlic vcllow colouf i>f liras-. While allowing the radiiuii to act 

 <in hy(ln)t>-ea peroxide in llic e\])!Tini('iit ])revionsl_v de-eribed, 

 wlicn^ rlie brass rod was cncdused in an atmosphere of ozone, 

 and air cniitainiiiii nmrc nxviicn Thin (irdinar\- air. there was 

 found on the part of the rod near the radium, a snudl quantity 

 of this dark grey substance. Some of this was scrai>ed off, care 

 being taken not to remove any of the brass. On analvzing this 

 substance it was found to contain only copper, there not l)eing 

 even so much as a trace of lead or zinc ])resent. What has 

 probably taken place is that the action oi' tlie raditun on the 

 brass in the prese'nce of oxygen has slowly converted the copper 

 of the alloy ti> copper oxide; the greater the amount o{ oxy- 

 gen present the more rapidly the change takes place. 



The results here given show that in many reactions the effect 

 of radium is to accelerate that action already going on, and in 

 the case of amygdalin and hydrochloric acid it may perhaps set 

 up a new action of its own, besides accelerating the hydrolysis 

 of the amygdalin into glucose, etc. Lastly the presence of 

 amygdalin may l>e detected by boiliiig a solution supposed to 

 contain it with a few dro})s of Fehling's solution and noting 

 whether or not the odour of ammonia is given off. 



The author's Ix^st thanks are due to Professor ^MacKay for 

 tlie interest he has shown in these experiments. 



Dai.iioisik IMvKKsiTY, lliilifax. N. S. 

 Ahiicli :j(l. lilOS. 



