64 THE EXTRACTIVE MATTERS OF THE LIQUOR SAXGUINIS. [BOOK I. 



experiments, under the direction of Salkowski, failed to obtain albumin 

 free from ash. Huizinga 1 by continued dialysis found that serum-albumin 

 contained from 0'36 to 0'56 p. c. of ash. Haas 2 was able from the fluid 

 of ascites to obtain serum-albumin containing only 0'3 p. c. of ash; he 

 found that its solutions were precipitated by alcohol and by ether; 

 when boiled, the solutions always became opalescent, and often yielded 

 precipitates. 



Are pep- It has been surmised that peptones, &c. which are 



tones present formed in such large quantities in the alimentary 

 in the serum? canal, and which are doubtless absorbed into the 

 blood, may be present as peptones in that fluid. The most recent 

 research, of Drosdoff, shews that the presence of peptones cannot be 

 demonstrated with certainty even in the blood of the portal vein 

 taken whilst absorption is progressing 3 . 



THE EXTRACTIVE- MATTERS OF THE PLASMA AND SERUM. 



By the term extractive matters, physiological chemists formerly desig- 

 nated organic substances present in very small quantities in the various 

 solids and liquids of the body, and extracted from them by various liquids, 

 especially by alcohol, but which could not be obtained in a sufficiently 

 pure condition to admit of their identification as definite proximate 

 principles. 



The progress of research has, to a very great extent, enabled us to resolve 

 the group of 'extractive matters,' obtained from most liquids and solids, into 

 its components ; still the term remains as a convenient one for the purpose 

 of grouping the organic constituents present in small quantities, and 

 capable of extraction by various liquids. 



The extractive matters present in the plasma all pass into the serum. 

 These bodies, although present in small quantities in these fluids, are yet 

 possessed of the highest physiological importance. It is more in accordance 

 with the plan of the present work to consider at length the individual 

 extractive matters of the blood in connection with the functions of the 

 body with which they are most closely related, and the author therefore 

 limits himself in this place to little more than an enumeration. As 

 indicating the method of treatment which has been adopted, the reader 

 is informed that the fats of the serum will be considered under digestion 

 and in connection with the chemistry of the nervous organs, sugar when 

 discussing the functions of the liver, urea and uric acid in connection 

 with the secretion of urine, creatine and creatinine when treating of 

 muscle. 



1 Huizinga, "Zur Darstellung des dialysirten Eiweisses." Pfliiger's Archiv, n. 

 pp. 392402. 



2 Haas : " Ueber das optische und chemische Verhalten einiger Eiweisssubstanzen, 

 insbeeondere <fer dialysirten Albumine." Pfliiger's Archiv, Vol. xn. pp. 378 410. 

 "Ueber die Eigenschaften des salzarmen Albumins," Prager medic. Wochenschrift, 

 1876, Nos. -8436 ; also Maly's Jahresbericht, Vol. vi. (1877), p. 5. 



3 Drosdoff, "Resorption der Peptone, des Rohrzuckers und der Indigoschwefelsaure 

 vom Darmcanal aus und ihr Nachweis im Blute der Vena portae." ZeitscJirift f. physiol. 

 Chem., i. 210232. 



