OEGANS AND LIVING TISSUES LEGENDRE. 



415 



The first experiments with artificial circulation in the isolated 

 heart were made iii Ludwig's laboratory and were improved by 

 Kronecker (fig. 1), but they were lunited to the frog and the inferior 

 vertebrates. The observation made b}" Arnaud (1891) of the heart 

 of the rabbit, that of Hedon and Gilis (1892) on the heart of a 

 criminal showed that that organ recommences to beat when defibri- 

 natcd blood is mjected under pressure into the coronary arteries, 

 and this led Langendorff (1895) to effect the survival of the heart 

 of mammals by means of artificial coronary circulation. Locke 

 (1901) substituted for defibrmated blood an artificial serum without 

 globules. Since then experiments on the survival of the heart 



Fig. 2. — The apparatus of Pachon for the study of the survival of the Lsolatcd heart of mammals. T, reser- 

 voir of oxygen under pressure; B, water bath assuring a constant temperature; R, A, S, regulators of 

 the temperatTire; T, M, thermometer and manometer for the senim at its entrance into the isolated 

 heart C; at the left a cylinder for registering the contractions of tho heart. 



have multiplied and become classic. Artificial circulation has kept 

 the heart of man contracting normally for 20 hours (Ivuliabko, 

 1902), that of the monkey for 54 hours (Hering, 1903), that of the 

 rabbit for 5 days (Kuliabko, 1902), etc. It has also enabled us to 

 study the influence upon the heart of physical factors, such as tem- 

 perature, isotonia; chemical factors, such as various salts and the 

 different ions; and even complex pharmaceutical products. Kuli- 

 abko (1902) was even able to note contractions m the heart of a 

 rabbit that had been kept in cold storage for 18 hours, and in the 

 heart of a cat similarly kept after 24 hours. 



The other muscular organs have naturally been investigated hi 

 a manner analogous to that which has been used for the heart; 



