URINE. 331 



dividual particles are usually darker, more clearly defined, and 

 larger than in kystein. The whole field of vision was likewise 

 bestrewed with numerous vibriones in active motion, and crystals 

 of ammoniaco-magnesian phosphate. When the pellicle became 

 thicker, precisely similar phenomena were observed, but the 

 vibriones were supplanted by a considerable number of monads ; 

 on the addition of acetic acid the crystals disappeared, while 

 the amorphous matter remained unaffected. On digesting the 

 pellicle in acetic acid, and adding ferrocyanide of potassium to 

 the filtered solution, a comparatively slight turbidity ensued, 

 but on macerating the pellicle in a dilute solution of pot- 

 ash, acidulating the filtered solution with acetic acid, heating, 

 and adding ferrocyanide of potassium after a second filtration, 

 a more decided turbidity was observed. From these experi- 

 ments I concluded that a protein-compound was present. The 

 white sediment, that occurred after the urine had stood for some 

 days, possessed a disagreeable, pungent, caseous odour : under 

 the microscope it presented the same appearance as the pellicle. 

 After repeatedly washing a portion of the sediment with water, 

 and then heating it with alcohol and a little sulphuric acid, 

 it developed a disagreeable fmit-like odour, reminding me of 

 butyric ether. [We shall presently show that the accuracy of 

 this observation has been thoroughly established by Lehmann.] 

 It results from the above observations, that kystein is not a 

 new and distinct substance, but a protein-compound, whose 

 formation is undoubtedly and closely connected with the lacteal 

 secretion. From the observations of Kane and myself, it seems 

 to follow that pregnancy may exist without the occurrence of 

 kystein in the urine ; if, however, there is a probability or pos- 

 sibility of pregnancy, and kystein is found in the urine, then 

 the probability is reduced almost to a certainty. We are un- 

 able to draw any positive inferences respecting the stage of 

 pregnancy from the appearance of the kystein. 



A deposit of caseous matter and earthy phosphates was fre- 

 quently observed by Golding Bird in the advanced stages of 

 pregnancy. The sediment is probably similar to Nauche's 

 kystein. 



Every urine left to itself forms a pellicle, more or less re- 

 sembling that of kystein. If formed soon after the urine is 

 discharged, it consists of earthy phosphates, which, from the 



