THE MICROSCOPE. 153 



the condition they were in being well described by the foregoing re- 

 marks. The pulps were alive. The dentine of the roots and necks 

 was supplied with a normal amount of living matter, but that in 

 both crowns did not appear normal, /. e., some of the canaliculi con- 

 tained the normal continuous fiber of Tomes, while in others very 

 near the fibrillse were broken up or segmented to some extent. 



I am very well aware that the bacterian might insist that I have 

 mistaken bacilli or bacteria for segmented fibrillar, but having never 

 found this appearance in the sound dentine of teeth rapidly decayed 

 nor in those wherein the process was moderately rapid, and having 

 studied the varieties of bacteria found in the decayed and softened 

 dentine, I can say that I know better, for bacteria and bacilli are not 

 found in sound dentine. 



I believe that what I have described as segmented fibrillae to be 

 a disorganization of the fiber of Tomes that is rarely met with. 

 The fact of hypersensitiveness led me to make a prolonged and 

 careful study of the fibrils that appeared continuous, believing that 

 through them sensation was conveyed to the pulp, but I was unable 

 to discover either an atrophy or hypertrophy of them, and they are 

 reserved for further study. But the fact is well demonstrated that 

 a low form of pulpitis has an observable effect upon the fiber of 

 Tomes in isolated cases. 



URINARY DEPOSITS. 



BY C. H. STOWELL. 



URATE OF SODA. — Urate of soda forms a very common urin- 

 ary deposit, and it is found in the urine of persons in good 

 health. It is held in solution in the healthy urine,, but it is fre- 

 quently precipitated. It appears, generally, in the form of amor- 

 phous, irregular, very small granules. It is slightly soluble in cold 

 water and is readily soluble in warm water; soluble in the alkalies 

 and in solutions of the alkaline carbonates and phosphates. If a 

 solution of pure urate of soda be prepared and the salt allowed to 

 crystallize, it will form small, acicular crystals. The deposit con- 

 taining urate of soda varies very much in color from a pale, white 

 cloudy precipitate to a pink, brown, or even dark red color. The 

 urine containing this deposit is never turbid when freshly voided; it 

 is only after the urine has cooled that the cloudiness occurs. Some 



