1171 



UROMASTIX. 



(JRSID.E. 



lin 



of lime ami magnesia ire naturally found in the urine, arising from 

 the disintegration of the oseeous tissue. Their deposit so at to form 

 calculi depend! on the absence of the acid phosphate of soda in which 

 they are soluble, and not to their redundance in the system. During 

 the deposit of the ammonUco-magnecian phosphate, the urine is some- 

 times neutral, often acid, and never alkaline, unless the deposited 

 phosphate is really a secondary result On exposing to heat urine of 

 this kind, the triple salt is deposited, the precipitation often being 

 attended with an evident evolution of carbonic acid. Dr. Bird ha 

 figured two distinct forma of triple phosphate, each containing a 

 different proportion of ammonia, and readily distinguishable by the 

 shape of their crystals. The first appears under the microscope of a 

 weak magnifying power as a series of beautifully-defined transparent 

 crystals, being either prisms or some modifications of them. The 

 second forms elegant stellar crystals, or thin crystalline lamina;, 

 resembling foliage. 



Whore this rait exists in combination with phosphate of lime, 

 forming the well-known fusible compound, the characters of the 

 urine scarcely differ from those met with in simply phosphatic secre- 

 tion. 



Chloride of Sodium. This substance seems to result from the kind 

 of food rather than the disintegration of the 'tissues, and thus it is 

 found varying in quantity according to the nature of the food. 



Soda, Potash, Ammonia. The two fixed alkalies exist in the urine 

 in combination with the sulphuric, phosphoric, muriatic, and lactic 

 acids : whilst ammonia is found in combination only with the hydro- 

 chloric, phosphoric, and uric acids. 



Lime. If to urine, deprived by filtration of its vesical mucus, an 

 excess of caustic ammonia be added, a very bulky precipitate is 

 thrown down. This precipitate (besides a minute quantity of ammonio- 

 phosphate of magnesia) contains the lime in union with phosphoric 

 acid. 



Magnesia, like lime, in combination with phosphoric acid, ia one of 

 the constituents of bone earth ; but it forma a very small part. It is 

 also a principal ingredient of certain urinary calculi, into two species 

 of which it enters. 



Silica, or Silic Acid, is reckoned by Berzeliiu amongst the constitu- 

 ent* of healthy urine, and it has been occasionally detected in urinary 

 calculi. 



For an account of the products only occasionally found in the urine, 

 see the article URINE, PATHduwv of, in ARTS ASD Sc. Drv. 



On examining the sediment of urine under the microscope, a 

 number of substances presenting definite forms will be seen. The 

 mucus-corpuscles have been referred to above, but there are other 

 morphological elements which probably supply the chemist with the 

 quantity of matter placed under the head of extractive matters and 

 mucus. These are as follows : 



1. The pavement-epithelium of the urinary passages and bladder, 

 cells of which are never wholly absent 



2. Tube-like or cylindrical bodies. These are casts of the tubes in 

 the kidneys, and are frequently found in large quantities in diseased 

 conditions of the organs. 



3. Spermatozoa, which are often found in nonuiU urine, arising 

 from natural 



4. Filamentous Fungi are developed in urine after it has been kept 

 Home time, and arises under the same circumstances as the various 

 forms of ferment Fungut. 



.".. hifutoria, especially those called Vibrio, are found present in 



The foreign substances which are accidentally found in the urine are 

 referred to in the article MICROSCOPE, Uses OF Tin:. 



(Bowman, Medical Chemutry ; Beale, The Microtcojte in iti Applica- 

 tion! to Chemical Medicine: Gregory, Handbook of Inorganic Chemiitry; 

 Hence Jones, On Animal Chemutry in ilt Application to Stomack and 

 Rtaal Dotaut; O. K. Day, Conlributiom to Urology; Britith and 

 Foreign Mrdico C/iirurgical Rrriew, July, 1855.) 



UKOMASTJX. IDRACOSIXA.J 



U'RSIDjE. Under the article BKAR will be found a full account 

 of the species of the genus Unut. This is a genus placed in the lost 

 edition of the 'Systema Nature:' that underwent the revision of 

 Linnamn, between Muitela and Didelphu, and includes the following 

 specie* arclot, mtle*, lotor, and Ituctu : in other words, it consists of 

 the True Bean, the Badger, the Raccoon, and the Wolverene or 

 Glutton. 



We shall here give an account of the other genera of Urtida, and 

 illuntnttions of the organisation of the genus Vrnu (Linn.) : 



The cylindrical bones of bears come nearer to those of man than 

 the earn* bones in any other quadruped : the femur especially, 

 although there is but a slight depression for the ligamentum teres, is 

 closely approximated to the same bone in the human skeleton ; and 

 hence the faculty postered by the bear of rearing itself on its hind- 

 legs and dancing. The caudal vertebras in every well-preserved 

 skeleton those in the Museum of the College of Surgeons for instance 

 extend beyond the pelvis. 



Dental Formula : Incisors, !; Canine*, inl; Molars, ?^? - 42. 

 I 1 77 



Skeleton of Polar Bear (I'rtut arctot, THalarctot maritimui). 



Procyon (Ston-.), the Raccoons, have the three last molar* with 

 blunt tubercles on their crowns. Muzzle pointed. Ears small. Tail 

 very long and hairy. No anal follicles. Six ventral mainline. Feet 

 pentadactyle : claws sharp ; the entire sole of the foot applied to the 

 ground, when the animal is (tationary only; in progression the heel is 



nbtdi 



K? 



Raccoon (Procyon'Jotor ; Vrnu lotor, Linn.). (E. T. Bennett.) 



