CHEMISTRY. 



137 



Chemical 



Eiamina- 



tion of 



Nature. 



Formic. 

 Acetic. 



Malic. 



Alkalies 

 found in 

 animals. 



Potajh, 

 Soda, 



Ammonia. 



Eartlu 

 found in 



animals. 



Lime, 



Magnciia, 



Silica. 



Metal* 

 found in 

 animals. 



Iron, 



Manganese 



Part* r> 

 nima!<. 



10. Formic acid has been hitherto found only in the 

 formica rtefa, or red ant. 



11. Acetic. This acid has been detected in urine by 

 Proust. It exists also in the formica rufa, or red ant, 

 as has been demonstrated by the experiments of Four- 

 croy and Vauquelin. It appears also, from the labours 

 of these philosophers and of Thenard, that the acid found 

 in milk is the acetic, disguised a little by holding some 

 salt; in solution. 



12. Malic acid. This acid has been lately detected 

 by Fourcroy and Vauquelin, in the acid liquid obtained 

 from the formica rufa. When this liquid is saturated 

 with lime, if acetate of lead be dropt into the solution, a 

 copious precipitate falls, which is soluble in acetic acid. 

 Fourcroy and Vauquelin exposed the precipitate to the 

 proper trials, and ascertained that it was initiate of lead. 



SECT. X. Of Alkalies, Earths, and Metals. 



I. All the alkalies have been found in the fluids of ani- 

 mals. 



1. Potash is rather uncommon in the human fluids ; 

 but it has been detected in the milk of cows, and it has 

 been found abundantly in the urine of quadrupeds. 



2. Soda exists in all the fluids, and seems always to 

 be combined with albumen. Phosphate and muriate of 

 soda are also found. It is this alkali which gives animal 

 fluids the property of tinging vegetable blues green. 



3. Ammonia has been detected by Proust in urine ; 

 and it is formed in abundance during the putrefaction of 

 most animal bodies. 



II. The only earths hitherto found in animals are lime, 

 magnesia, and silica. 



1. Lime exists in great abundance in all the larger ani- 

 mals. Combined with phosphoric acid, it constitutes 

 the basis of bones, while shells are composed of carbo- 

 nate of lime. Phosphate of lime is found also in the 

 muscles and other solid parts, and it is held in solution 

 by almost all the fluid-. 



2. Magnesia has been detected in human urine by 

 Fourcroy and Vauquelin, combined with phosphoric acid 

 and ammonia. It constitutes also sometimes a compo- 

 nent part of the urinary calculi. 



3. Silica has not hitherto been detected in any of the 

 component parts of animals, except hair ; but Fourcroy 

 and Vauquelin found it in urinary calculi. 



III. The metals found in animals are two ; namely, 

 iron and manganese. 



1. Iron combined with phosphoric acid is a constitu- 

 ent part of the blood. Its presence was first ascertained 

 by Mcnghini, who proved at the same time that it does 

 not exist in the solid parts of animals. It is said to exist 

 also in bile. 



2. Manganese has been found in human hair, but 

 scarcely in any other animal substance. 



CHAP. II. 



Parts of Animals. 



THE different substances which compose the bodies of 

 animals may be arranged under the following heads : 

 1. Bones and shells. 7. Glands. 



'2. Horns and nails. 8. 



Muscles. 9. 



*. Skin. 10. 



">, Membranes. ] 1 . 



<>. Tendons and ligaments. 

 . vr. FAIT i. 



Besides these substances, which constitute the solid 

 parts of the bodies of animals, there are a number of 

 fluids, the most important of which is the blood, which 

 pervades every part of the system in all the larger ani- 

 mals. The rest are known by the name of secretions, 

 because they are formed, or secreted as the anatomists 

 term it, from the blood. The principal animal secretions 

 are the following : 



9. Humours of the eye. 



10. Mucus of the nose, &c. 



11. Sinovia. 



12. Semen. 



13. Liquor of the amnios. 



14. Poisonous secretions. 



15. Air. 



Chemical 

 Examina- 

 tion of 

 Nature. 



Brain and nerves. 



Marrow. 



Hair and feathers. 



Silk and similar bodies. 



1. Milk. 



2. Eggs. 



3. Saliva. 



4. Pancreatic juice. 



5. Bile. 



6. Cerumen. 



7. Tears. 



8. Liquor of the pericardium. 



Various substances are separated either from the blood 

 or the food, on purpose to be afterwards thrown out of 

 the body as useless or hurtful. These are called^wrre- 

 tions. The most important of them are, 



1. Sweat. 



2. Urine. 



3. Fzces. 



Besides the liquids which are secreted for the differ- 

 ent purposes of healthy animals, there are others which 

 make their appearance only during disease, and which 

 may therefore be called morbid secretions. The most 

 important of these are the following : 



1. Pus. 



2. The liquor of dropsy. 



3. The liquor of blisters. 



To these we must add several solid bodies, which are 

 occasionally formed in different cavities, in consequence 

 of the diseased action of the parts. They may be called 

 morbid concretions. The most remarkable of them are 

 the following : 



1. Salivary calculi. 



2. Concretions in the lungs, liver, brain, &c. 



3. Intestinal calculi. 



4. Biliary calculi. 



5. Urinary calculi. 



6. Gouty calculi. 



These different substances shall form the subjects of 

 the following Sections : 



SECT. I. OfBonet, Shelfs, and Crusts. 



By bonet are meant those hard, solid, well-known sub- Bone. 

 stances, to which the firmness, shape, and strength of 

 animal bodies are owing ; which, in the larger animals, 

 form, as it were, the ground-work upon which all the 

 rest is built. In man, in quadrupeds, and many other 

 animals, the bones are situated below the other parts, and 

 scarcely any of them are exposed to view ; but shell-fish 

 and snails have a hard covering on the outside of their 

 bodies, evidently intended for defence. As these cover- 

 ings, though known by the name of shells, are un- 

 doubtedly of a bony matter, we shall include them in this 

 Section. 



1. Bones. 



The bones are the most solid parts of animals. Their Their pro- 

 texture is sometimes dense, at other times cellular and po- pertiee. 

 rous, according to the situation of the bone. They are 

 white, of a lamellar structure, and not flexible nor soften- 

 ed by heat. Their specific gravity differs in different 

 parts. That of adults' teeth is 2.2727 ; the specific 

 gravity of children's teeth is 2.0833. 



