766 



DR FRASER ON THE PHYSIOLOGICAL ACTION 



In my first experiments, the frog was merely tied down in the manner usual 

 when the circulation in its web is being microscopically examined, but it was 

 found impossible to prevent movements so absolutely as was required to retain 

 the selected vessels in the field of the microscope. I ultimately found it necessary 

 to adopt Lister's recommendation of dividing the spinal cord several hours 

 before the observations were begun. 



Experiment LXII. 



I divided the spinal cord at the occiput of a light-coloured frog weighing 529 grains, and, 

 six hours afterwards, placed the web of one of its feet on the stage of a microscope. A small 

 artery, a minute branch and a vein were selected and placed conveniently for measure- 

 ment* 



A = diameter of larger artery ; B = diameter of smaller artery ; and C = diameter of vein. 



Time. 



A. 



B. 



C. 



Notes. 



15 minutes before 



) 









administration 



V 8 



25 



6-5 





of Calabar bean 



J 









10 Do. 



80 



2-5 



6-5 



Circulation free. 



5 Do. 



80 



25 



6-5 



Four grains of extract, in twenty minims of 











Time after administra- 









distilled water, were injected into the sub- 



tion of poison. 









cutaneous tissue of the abdomen. 



6 minutes, 



7-8 



2-5 



6-5 





9 



6-5 



2-0 



6 





10 „ 



5-9 



1-8 



5-7 





12 „ 



68 



20 



6-2 



Circulation feeble, oscillating sometimes ; 

 vessels are crowded. 



14 „ 



7-0 



2-0 



6-5 





15 



8-5 



30 



65 





17 „ 



85 



3-0 



70 



Almost no circulation. 



19 „ 



90 



3-0 



7 5 



Faint oscillations only in the artery ; con- 

 siderable crowding in all the vessels. 



23 „ 



8 5 



30 



7-5 





29 „ 



85 



30 



7-5 



Complete stasis. 



36 „ 



8-5 



30 



7-5 





39 „ 



9-0 



3-0 



75 





1 hour 



90 



3-0 



7-5 





2 hours 



9 



3-0 



7-5 





Experiment LXIII. 



The web of a frog, of 590 grains weight, was placed in the field of a microscope, after the 

 animal had been prepared in the manner described in the previous experiment. 



* Nachet's eye-piece No. 1, and object-glass No. 3, were employed; and the measurements 

 represent divisions of an eye-piece micrometer, each of which equals 3-5-jth of an inch with the above 

 glasses. 



