22 i 



DR. ORD. 



Concurrently with the above observations I was engaged 

 in a wider investigation of somewhat similar nature. 



In December, 1868, while examining some urine I met 

 with dumb-bells of a kind quite new to me ; and, consulting 

 Dr. Beale's work on 'Urinary Dejiosits' (3rd ed.), I found 

 that he had made drawings of dumb-bells of oxalate of lime 

 contained in transparent casts of renal tubes, accompanied 

 by octohedra floating in the surrounding fluid. In his re- 

 marks upon these forms I found arguments adduced — 1st, to 

 prove that the dumb-bells were, in fact, composed of oxalate 

 of lime ; 2nd, to explain the assumption of the dumb-bell 

 form in such cases by considerations founded upon the in- 

 vestigations of Mr. Rainey, which show that the presence of 

 viscid organic matter prevents crystalline substances from 

 assuming their usual form, and causes the crystalline matter 

 to be deposited in spherical or dumb-bell shape. I resolved 

 ^to apply a modification of Mr. Rainey's plan of experiment 

 to the determination of some of the conditions under which 

 dumb-bells might be formed; to fix with more certainty the 

 relations between the octohedron and the dumb-bell of oxa- 

 late of lime ; to try, in fact, to turn the one into the other, 

 and set rest any remaining doubt as to their identity. The 

 first experiments were made in the following way. 



Some perfectly clear jelly prepared from isinglass, was 

 melted in a flat-bottomed jar, in quantity enough to form a 

 layer three quarters of an inch deep. In this, while still 

 liqviid, a number of glass tubes, each about four inches long, 

 half an inch in diameter, and open at both ends, were placed 

 upright, so that each tube was immersed to the depth of 



