Essentials of chemistry : inorganic and organic, for the use of students in medicine / by R.A. Witthaus.

  • Rudolph August Witthaus
Date:
1879, ©1878
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Licence: Public Domain Mark

Credit: Essentials of chemistry : inorganic and organic, for the use of students in medicine / by R.A. Witthaus. Source: Wellcome Collection.

Provider: This material has been provided by the Harvey Cushing/John Hay Whitney Medical Library at Yale University, through the Medical Heritage Library. The original may be consulted at the Harvey Cushing/John Hay Whitney Medical Library at Yale University.

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    and the almost insoluble uric acid is precipitated and might easily be mistaken for albumen. 1021. How may minute traces of albumen be de- tected? Place in a test-tube a layer of nitric acid about 2 centim. in thickness, then, with a glass tube, carefully float upon the surface of this a layer of the urine in such a manner that the liquids do not mix ; if albumen be present a cloudy ring appears at the point of junction of the two layers, the borders of the cloud being sharply denned. A cloudy ring may be formed by the presence of an excess of urates, but in this case it is not at, but above the point of junction of the layers, and its upper border is not sharply denned, but is ragged and fades off gradually. 1022. Give a process for determining the quantity of albumen in urine. Heat a known volume of acid urine to near the boiling point, collect the coagula upon a weighed filter, wash with water, dry the filter with adhering albumen at 100°, weigh. The difference between the two weighings indicates the quantity of dry albumen in the volume of urine used. [Some au- thors direct to weigh the filter and albumen wet, when this is done there is no approach to accuracy as it is impossible to judge how much water is be- ing weighed.] 1023. Why should albuminous urine always be examined microscopically ? To determine the presence or absence of blood or pus corpuscles, spermatozoa and casts. When the urine contains blood, pus or spermatic fluid it is always slightly albuminous, the presence of albu-