Full resolution (JPEG) - On this page / på denna sida - XIV. Urine - II. Organic Physiological Constituents of Urine
<< prev. page << föreg. sida << >> nästa sida >> next page >>
Below is the raw OCR text
from the above scanned image.
Do you see an error? Proofread the page now!
Här nedan syns maskintolkade texten från faksimilbilden ovan.
Ser du något fel? Korrekturläs sidan nu!
This page has never been proofread. / Denna sida har aldrig korrekturlästs.
PROPERTIES AND REACTIONS OF URIC ACID. 707
Ascoli, Izar, Bezzola and Preti * have studied the remarkable ability of
the liver of destroying uric acid in the blood by transfusing the arterial blood
through this organ and qd transfusing the blood, saturated with C02 , they have
regenerated the uric arid. It is not known what becomes of the uric acid in
these cases and from what substance the regeneration occurs. Preti has shown
that in the regeneration a combined action of an enzyme in the blood with a
co-enzyme of the liver, takes place.
From this power of the various organs of destroying uric acid it
follows that the quantity of uric acid eliminated is not a sure indication
of the amount of the acid formed. We must, therefore, admit that a
part of the uric acid formed in the body is destroyed in a manner similar
to that introduced from without. Burian and Schur 2
have indeed
suggested a factor, the so-called " integral factor," with which the quan-
tity of uric acid eliminated in the twenty-four hours must be multiplied
in order to find the quantity of uric acid formed during this time. Such
calculations are necessarily very uncertain and are for the present not
admissible.
Properties and Reactions of Uric Acid. Pure uric acid is a white,
odorless, and tasteless powder consisting of very small rhombic prisms
or plates. Impure uric acid is easilv obtained as somewhat larger,
colored crystals.
In rapid crystallization, small, thin, four-sided, apparently colorless,
rhombic prisms are formed, which can be seen only by the aid of the
microscope, and these sometimes appear as spools because of the round-
ing of their obtuse angles. The plates are sometimes six-sided, irregularly
developed; in other cases they are rectangular with partly straight and
partly jagged sides; and in other cases they show still more irregular
forms, the so-called dumb-Veils, etc. In slow crystallization, as when
the urine deposits a sediment or when treated with acid, large, invariably
colored crystals separate. Examined with the microscope these crystals
always appear yellow or yellowish brown in color. The most common
type is the whetstone shape, formed by the rounding off of the obtuse
angles of the rhombic plate. The whetstones are generally connected,
two or more crossing each other. Besides these forms, rosettes of pris-
matic crystals, irregular crosses, brown-colored rough masses of broken-
up crystals and prisms occur, as well as other forms.
Uric acid is insoluble in alcohol and ether; it is rather easily soluble
in boiling glycerin, but very insoluble in cold water, in 39480 parts at
18° C. (His and Paul), and in 15505 parts at 37° (Gudzent). At
this temperature, according to His and Paul, P. 5 per cent of the uric
acid is dissociated in the saturated solution. Because of the reduction
1
See Zeitschr. f . physiol. Chem., 58, 62, 64 and 63.
2
Pfliiger’s Arch., 87.
<< prev. page << föreg. sida << >> nästa sida >> next page >>
