316 



Scientific Proceedings (130) 



scattered upon the glass and rubber wall of the collecting tube. 

 What determines this punctate localization? In certain instances, 

 of almost pure calcium carbonate concretions, the answer is plain. 

 These form in the midst of organic debris, not infrequently 

 around bits of talc from the tube surface. In other cases minute, 

 rounded, pigmented particles from the bile lodge upon the tube 

 wall, and stone formation takes place upon these as nuclei. To 

 trace the source of such particles and their significance we have 

 made day to day studies of the sediment from sterile 24 hour 

 specimens of bile centrifuged on removal from collecting bal- 

 loons devoid of air. Also we have followed the early stages of 

 calculus formation in the collecting tubes of the same animals. 



The bile was found to yield formed elements identical with 

 those later recovered from the tube system and from the interior 

 of stones forming upon the walls of the latter. The nature and 

 the amount of the sediment vary with the condition of the animal. 

 For a day after the operation whereby intubation is effected it 

 may consist merely of mucus, which later is seldom met with. 

 Usually one obtains from the specimen of the second 24 hours 

 after operation and perhaps more abundantly from that of the 

 third, a slight brown deposit, made up, as the microscope shows, 

 of minute, highly refractile, translucent, yellow-brown granules. 

 The shape of these tends to be spherical, but is rendered various 

 by the partial merging of the spheres. They fracture radially on 

 pressure into rosettes, are anisotropic, and fail to lose this char- 

 acter or their shape when heated to 100° C. The refractile mate- 

 rial of which they are mainly composed is insoluble in water, 

 alcohol, ether, chloroform, or acetone, but dissolves readily in 

 chloroform after treatment with acid, as also in a dilute watery 

 solution of hydrochloric acid, leaving the brown pigment and a 

 mucous "shadow" behind. They are colored deep blue with Nile 

 blue sulphate but are unaffected by the stains for neutral fats, 

 and are Gram-negative. Such granules serve as nuclei for the 

 deposition of calcium carbonate and calcium bilirubinate, as fur- 

 ther study of the bile has shown. In the secretion of the third 

 to fifth day after operation, but usually not later, they are pres- 

 ent but encrusted with a deposit of more or less pigmented crys- 

 tals composed of a mixture of the salts mentioned. Thereafter 

 this crystalline matter alone is to be found, unless there occurs 

 some liver disturbance, when a shower of the brown granules 



