THE IMPROVED ART OF FARRIERY 36^ 



microscope can even perceive in its uncoagulated 

 state. On allowing it to stand at rest and to be ex- 

 posed to the air, it separated into what are called 

 the crassamentum and the serum. The crassa- 

 mentum consists chiefly of the red globules, joined to- 

 gether by another substance, called the coagulable 

 lymph ; the chemical properties of these globules ai e 

 not as yet understood, but they seem to contain the 

 greatest quantity of iron found in the blood. 



The serum is a yellowish subviscid liquor, having 

 little sensible taste or smell; at a heat of 160 Faren- 

 heit's thermometer it is converted into a jelly. This 

 coagulation of the serum is also owing to its contain- 

 ing a matter of the same nature with that of the cras- 

 samentum, viz., the coagulable lymph ; whatever then 

 coagulates animal blood, produces that effect on this 

 concrescible part. 



Ses^eral causes, and many different substances, are 

 capable of effecting this coagulation, such as contact 

 of air, heat, alcohol, mineral acids, and their combina- 

 tions with earths, as alum, and some of the metallic 

 salts. The more perfect neutral salts are found to pre- 

 vent the coagulation, such as common salt and nitre. 



Of the fluids secreted from the blood, there are a 

 great variety in men and other animals. 



The excrementitious and redundant fluids are those 

 which afford, in general, the greatest quantity of vola- 

 tile alkali, and empyreumatic oil. There are also 

 some of the secreted fluids, which, on a chemical 

 analysis, yield products in some degree peculiar to 

 themselves. Of this kind is the urine, which is found 

 to contain in the greatest abundance the noted salt 

 formed from the phosporic acid and volatile alkali. 

 The fat, too, has been said to differ from other animal 

 matters in yielding, by distillation, a strong acid, but 



3 B 



