1901.] Properties of the Arterial arid Venous Walls, 143 



M I i i i i i i r i 



20 40 60 80 100 120 140 160 180 200 



Fig. 24. — Carotid (ox), relaxed, having been kept in defibrinated blood for several 

 days. Length (between ligatures) 14 mm. Diameter of lumen 5 mm. 



i i i I i i r rnrH--Tn-nr-T-^ 



O 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360 380. 400 420 



Fig. 25. — Second elevation of pressure in same portion of artery as in fig. 24, after 

 an interval of 30 minutes. Great increase in distensibility, with comparatively 

 low pressures. After the expansion has declined very greatly (pressure of 

 300 mm., &c.) there is again a slight increase of expansion between 320 mm. 

 and 420 mm. 













H l i i i 



20 -40 60 80 100 120 140 160 180 200 



Tig. 26.— Carotid (ox), relaxed by freezing for 5 — 6 hours. Lumen 5 — 6 mm. 

 Length of artery 19 mm. 



freezing is given by figs. 24 and 26, the nature of the results obtained 

 with arteries relaxed by other methods will be seen from the following 

 instances. The amount of expansion is indicated by the movement of 

 oil in the graduated tube stated in millimetres : — 



Carotid (Ox) relaxed by Potassium Sulphocyanide. — A contracted artery 

 37 mm. long, with lumen of 3 mm., and thickness of wall nearly 2 mm., 

 was put into 20 per cent, solution of potassium sulphocyanide for an 

 hour or two. It was then found to be 34 mm. in length, with lumen 

 about 5 mm., and thickness of wall 1*5 — 1*75 mm. Eigidity gone. 

 Length of portion used (measured between ligatures) 17 mm. Pressure 

 raised in usual way. 



Pressure. — 



20 



40 



60 



80 



100 



120 



140 



160 



180 





200 



220 



240 



260 



280 



300 



320 



340 



360 





380 



400 



420. 















Expansion. — 



14 



13 



9 



8 



6 



6 



5-5 



4-5 



4-5 





4-5 



5 



5 



55 



5 



5 



5 



4-5 



4>5 





4-5 



4-5. 

















L 2 



