432 



Mr. A. A. Campbell Swinton. 



VIII. Similar to VII, except that the preponderance of Antitoxin was 

 greater, viz., 0'000075 gram of venom and 1 c.c. of serum per kilo- 

 gram of body weight in each case. 



. Similar to VII and VIII, but the preponderance of Serum is still 

 greater, viz., 0'00005 gram of venom and 1 c.c. of serum per kilo- 

 gram, of body weight in each case. 



The expenses involved in the foregoing research were in part 

 defrayed from a grant made by the Government Grant Committee of 

 the Royal Society. 



" On the Source of the Rontgen Rays in Focus Tubes." By 

 ALAN A. CAMPBELL SWINTON. Communicated by Lord 

 KELVIN, F.R.S. Received June 7, Read June 16, 1898. 



The writer has already described (" Some new Studies in Cathode 

 and Rontgen Radiations," a discourse given at the Royal Institution 

 on February 4, 1898) how he has found it possible to study by 

 means of pin-hole photography the active area on the anti-cathode of 

 a focus tube from which the Rontgen rays proceed. 



