98 Chapter VI 



veins. It was then easy to divert the blood from these vessels into 

 the cannula, and measure the rate of flow as it emerged. 



The Salivary Glands. The evidence which exists with regard to 

 the submaxillary gland is of the same general character as that which 

 we have given for the kidney. In this case also the deficiency lies on 

 the side of quantitative proof of the amount of work done. It is 

 known however that saliva is always poorer in salts than is plasma, 

 though the two differ when the secretion is less rapid than when 

 it is slow. We can therefore affirm positively that whenever the 

 gland secretes it must do positive work, inasmuch as the secretion 

 differs in its salts from the plasma, though we are unable to state 

 precisely even the minimal value of such work. 



Of the salivary glands the submaxillary is that on which most work 

 has been done. 



The gross fact is that stimulation of the chorda tympani produces 

 an increase in the metabolism of the gland. This could be shown 

 even in the old days of the blood-gas pump. The following are some 

 data from the dog. 



Gaseous exchange in c.c. per minute (u) . 



Besting Active chorda 



Exp. O 2 C0 2 2 C0 2 Saliva secreted per mm. 



11(1) 0-32 0-20 1-20 1'58 1'6 c.c. 



,,(2) 0-30 0-20 0-93 0'60 1'6 c.c. 



,,(3) 0-29 0-20 0-59 0'75 1-3 c.c. 



IV 0-12 0-17 0-25 0-25 0-9 c.c. 



V 0-12 0-12 0-54 0-60 I'O c.c. 



VI 0-56 0-60 1-06 1-86 1-0 c.c. 



In the few experiments which have been performed the amount 

 of oxygen used by the gland per cubic centimetre of saliva is more 

 uniform than might have been expected. 



Kate of flow of saliva 

 Exp. per min. in c.c. Oxygen per c.c. of saliva 



1 2-1 0-48 

 3-2 0-45 

 2-5 0-43 



2 1-8 0-66 

 1-55 0-60 

 1-2 0-5 



3 0-37 1-05 

 1-05 1-00 



4 1-4 0-50 

 2-1 0-50 

 2-5 0-44 



