MAXUAL OF AGEICULTUEE. 249 



clot. In the first stage of coagulation its total constituents 

 appear as one jelly-looking mass, but in a little the serum oozes 

 thence as a yellowish slimy fluid. The corpuscles, however, 

 remain contained in the fibrin. The serum contains about 8 per 

 cent, of albumen, and with the exception of the fibrin and the 

 corpuscles, the whole constituents of the blood. Eoscoe gives the 

 following graphic formula as the average composition of the 

 blood : — 



Coagulum or Clot, ( ^^^^^^ • ' ' ' ^''^^ J 13-0 



° ' (.Corpuscles . . . 12-/0 ) 



( Water . . . 79 •0( 



Serum, . . U^l?^'^. ' ' ' n n^ ^ ^''0 



' j r atty matters . . 0"06 ' 



' Salts (inorganic) . , 0"9^ 



100-0 



The analysis of the inorganic or mineral matter remaining in 

 the ash, by Enderline, is as follows: — 



Phosphate of soda, . . , , 16*77 



Chloride of sodium, .... 59'34 



Chloride of potassium, . . . 6"12 



Sulphate of soda, .... 3-85 



Phosphate of magnesia, . . . 4'19 



Oxide, with a little phosphate of iron, . 8.28 



Sulphate of lime, and loss, . , . 1*45 



The heart, by its continual alternate muscular contraction and 

 expansion, keeps up an uninterrupted circulation of the blood 

 through the whole animal frame. There are four cavities in the 

 heart, two auricles and two ventricles. At either side of the 

 heart respectively are an auricle and a ventricle. The auricle of 

 the left side opens directly into the ventricle of the same side. 

 And so is it at the heart's right side. But the whole course of 

 the circulation intervenes between right and left auricles and 

 ventricles respectively. The contraction then of the left auricle 

 filled with blood forces it into the corresponding ventricle, which, 

 at the same time, expands in order to receive it. Next, the con- 

 traction of the left ventricle throws its contents into the main 

 arteries, forcing it along them into all their branches throughout 

 tlie body, and into their capillaries as well — the minute vessels 

 closely interlaced, wliich permeate all the corporeal tissues. From 

 these delicate tubes the blood enters the veins, and through them 

 is forced back to enter the heart's right auricle ; whereupon is 

 completed the systemic circulation, or tliat whereby every part 

 of tlie body receives an unfailing constant supply of nutritive 

 blood. 



As in the former instance, the right auricle pumps the blood into 

 the right ventricle, whence it enters the pulmonary artery, and 

 through it the lungs. In the lungs it is exposed to the action 



