1901.] Properties ot the Arterial and Venous Walls. 139 



the longitudinal strip the second loading gives a result essentially 

 similar to the first. 



Fig. 20. — Carotid (ox), contracted. Longitudinal strip. Second loading after 

 interval of 12 minutes. 



Jugular Vein. — Transverse* and longitudinal strips give results very 

 similar to relaxed arteries, though of course much smaller weights are 

 required to stretch them ; increments of 5 grammes were used instead 

 of 20 grammes. 



When stretched a second time, the difference in elongation is much 

 slighter than in arteries ; a longitudinal strip of vein may indeed show 

 no appreciable difference. (Figs. 21 and 22.) 



Contracted Artery treated with Salicyl-sidphonic Acid. — A contracted 

 artery which was left in 2 per cent, watery solution of salicyl-sulphonic 

 acid for 24 hours with the result that its proteid constituents were pre- 

 cipitated, gave a series of elongations almost proportional to the 

 weights employed, recalling the results got with iron wire or india- 

 rubber. This is well seen in fig. 23. 



A second application of the weights — if the first stretching was not 



* Cf. Braune's 'Beitrage z. Anat. u. Phys.,' 1874 p. 7, and Bardeleben's 

 ' Jenaische Zeitschrift,' vol. 12, p. 40, 1878, on the changes in length of veins when 

 weighted. 



