Volume Ii Part 282
(_c._) The solution (No. 2) is now added more liberally, and thoroughly mixed with the contents of the beaker by means of a gla.s.s rod; a copious white precipitate is being formed. The operation is completed, when, of course, no more precipitate is thrown down.
(_d._) This point is ascertained by means of the solution of carbonate of soda (No. 3), to a few isolated drops of which dotted about a white plate, or slab, or placed on a watch gla.s.s, give, when mixed by means of the stirring rod with a drop of the turbid mixture from the beaker, a yellow tinge, owing to the formation of hydrated oxide of mercury.
(_e._) The quant.i.ty of solution of mercuric nitrate that it has taken to produce the above reaction is then noted down, and from this the portion used before the occurrence of the turbidity is deducted, the remainder, of course, being the amount required to precipitate the urea. By bearing in mind the statement already made that 10 grain-measures of the mercurial solution indicate 01 grain of urea, the quant.i.ty excreted in 24 hours may be arrived at by a very easy and obvious calculation.
_Dr Davy's method of estimating Urea._ This consists in the decomposition of a known quant.i.ty of urine by sodium hypochlorite, the amount of urea being calculated from the resulting nitrogen. A gla.s.s tube, 12 or 14 inches in height, and graduated to tenths and hundredths of a cubic inch, is filled to more than a third of its length with mercury; a measured quant.i.ty of urine, varying from a quarter of a drachm to a drachm, is next poured into the tube, which is then filled up with a solution of sodium hypochlorite (the liquor sodae chlorinatae of the Dublin Pharmacopia). This latter must be poured in quickly, and the open end of the tube immediately closed with the thumb. The tube is then shaken to ensure admixture between the urine and hypochlorite, and stood with the open end downwards in a cup filled with a saturated solution of common salt; the mercury escapes into the tube, its place being filled by the solution of salt, which being heavier than the mixture of urine and hypochlorite, retains them in the upper part of the tube. The urine becomes soon decomposed, the carbonic acid, which is one of the products of its decomposition, being absorbed by the excess of chloride of sodium present, whilst the liberated nitrogen bubbles up to the top of the tube. When no more evolution of gas takes place, the volume of nitrogen is read off, and from its amount the quant.i.ty of urea present in the amount of urine experimented upon is calculated: one-fifth of a grain of urine = 03098 parts of a cubic inch of nitrogen at 60 Fahr. and 30" barometric pressure.
_Haughton's method of estimating Urea from the specific gravity of the Urine._ After having measured the urine voided during 24 hours, and determined the specific gravity of the whole collected amount, and then consulting the accompanying table, compiled by Professor Haughton, the number of grains of urea excreted per diem is immediately ascertained.
This quant.i.ty will be shown by the figures which stand at the points where the lines running respectively from the number of fluid ounces and the 'specific gravity' intersect each other. Thus, suppose the daily amount of urine to have been 30 ounces, and the specific gravity 1006, the number of grains of urea contained in it will be 85. This method is inserted for urines containing sugar and alb.u.men.
_Determination of the Water._ The amount of water in any sample of urine may be determined by weighing 1000 grains of the recently excreted urine into a counterpoised platinum or porcelain dish, and ascertaining the loss it has undergone after evaporation to dryness. The operation should be performed as speedily as possible. The best plan is to concentrate the urine in a water bath, the evaporation should be continued _in vacuo_ over strong sulphuric acid, until the weight of the residue remains constant.
By way of control, another sample of the same urine, consisting of 500 grains, may be operated upon at the same time, and under the same conditions.
URINARY DEPOSITS, &c. These differ from the alb.u.men, sugar, bile, &c., previously described, in being insoluble in abnormal urine. Sometimes they are diffused throughout the whole body of the urine, when they give it an opaque appearance. Sometimes they may be met with floating on its surface; at others they are only partially diffused through the fluid, frequently in the form of a transparent or opaque cloud, when they occupy a considerable s.p.a.ce; whilst very often they occur in a crystalline or granular form, deposited sometimes at the bottom and sometimes at the sides of the vessel holding the urine.
Of the numberless insoluble substances met with in urine, both in health and disease, our limits will only permit us to notice those which are most important, and of frequent occurrence.
For the detection of the generality of these the microscope is indispensable. An instrument magnifying 200 to 220 diameters (1/4 of inch objective) will generally be found sufficiently powerful, and in some instances an inch objective, magnifying 40 diameters (as in the larger forms of crystalline deposit) will answer all the purposes.
Some of the varieties of these deposits admit of a double examination, viz. a microscopical and chemical one. When this is the case, the particulars applying to each kind of investigation will be given.
_Mucus._ Mucus is always present in small quant.i.ty in healthy urine, in which it shows itself within a few hours after the urine has been excreted in the shape of a transparent cloud towards the bottom of the vessel containing the urine.
_Pus._ The presence of pus in urine is indicated by an opaque, more or less bulky, cream-like deposit at the bottom of the vessel holding the urine, to which some separated pus globules, finding their way to the supernatant liquid, give an appearance of slight turbidity. By shaking the vessel the whole of the liquid becomes turbid, owing to the equal dissemination through it of the pus globules. The pus again deposits on standing. A small quant.i.ty of alb.u.men is always met with in the clear part of urine which contains pus; the alb.u.men being derived from the _liquor puris_, the liquid by which the pus-corpuscles are surrounded.
Whenever it can be obtained in sufficient quant.i.ty, pus should always be examined chemically, as follows:--The supernatant urine being decanted, the suspected sediment is shaken up with liquor pota.s.sae, when if it become converted into a gelatinous, viscid substance, incapable of being dropped from the tube, and when poured from it running as a slimy and almost continuous ma.s.s, it may be p.r.o.nounced pus. This same gelatinous viscid ma.s.s is met with in alkaline urines containing pus, adhering to the sides of the vessel in which the urine is placed, where it has been formed by the action of the carbonate of ammonia (caused by the decomposition of the urea) upon the pus. The reaction upon the pus is the same as that which takes place when liquor pota.s.sae is employed. The stringy viscid substance due to the last cause is frequently, but erroneously, termed _mucus_.
Professor HAUGHTON'S _Table for the Estimation of the Daily Excretion of Urea from the Specific Gravity_.
-------+----------------------------------------------------------- Fluid
Specific Ounces.
Gravity.
+----+----+----+----+----+----+----+----+----+----+----+----+----
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015 -------+----+----+----+----+----+----+----+----+----+----+----+---- 20
35
36
43
57
71
85
100
103
106
119
130
136
142 22
38
40
47
62
78
95
110
113
116
130
149
142
156 24
42
43
51
68
85
101
120
123
127
142
156
163
170 26
45
47
55
73
92
110
130
131
137
153
169
176
184 28
48
50
59
79
99
118
140
144
148
165
182
190
198 30
52
54
64
85
106
127
150
155
159
177
195
204
213 32
55
57
68
90
113
135
160
165
169
188
208
217
227 34
58
61
72
96
120
144
170
175
180
200
221
231
241 36
61
64
76
102
127
153
180
185
191
212
234
244
255 38
65
68
80
108
134
161
190
195
201
224
247
258
269 40
69
72
85
114
142
170
200
206
212
236
260
272
284 42
74
75
89
119
148
178
210
216
222
247
273
285
298 44
76
79
93
125
156
186
220
226
233
259
286
299
312 46
80
82
96
130
163
195
230
236
243
271
299
312
326 48
84
86
101
136
170
203
240
246
254
283
312
326
340 50
87
90
106
142
178
212
250
257
265
295
325
340
355 52
90
94
110
147
185
220
260
267
276
307
338
353
369 54
94
98
114
153
192
229
270
277
286
319
351
367
383 56
96
100
119
159
199
238
280
288
297
331
364
380
397 58
100
104
123
165
206
246
290
298
308
343
377
394
411 60
104
108
128
171
213
255
300
309
310
355
391
408
426 62
108
110
132
176
220
263
310
319
329
404
421
440
468 64
110
114
136
182
227
271
320
329
340
378
417
435
454 66
114
118
140
187
234
280
330
340
351
390
431
448
468 68
116
122
144
193
240
288
340
350
361
402
443
462
482 70
120
126
149
199
248
297
350
361
372
414
456
476
497 72
122
128
153
204
255
305
360
371
382
425
469
489
511 74
126
132
157
210
262
314
370
381
393
437
482
503
525 76
130
136
161
216
269
323
380
391
404
449
595
516
539 78
134
140
165
222
276
331
390
401
414
461
508
530
553 80
139
144
170
228
284
340
400
412
445
473
521
544
568 --+----+----+----+----+----+----+----+----+----+----+----+----+----
-------+----------------------------------------------------------- Fluid
Specific Ounces.
Gravity.
+----+----+----+----+----+----+----+----+----+----+----+----+----
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028 -------+----+----+----+----+----+----+----+----+----+----+----+---- 20
151
160
196
233
241
249
257
265
274
276
278
279
280 22
166
176
215
257
265
274
282
292
301
303
305
306
308 24
181
192
235
280
289
299
308
319
329
331
333
334
336 26
196
208
254
303
313
324
334
346
356
359
360
362
364 28
221
224
274
326
337
349
360
372
383
386
388
390
392 30
226
240
294
349
361
374
386
399
411
414
416
418
420 32
241
256
313
373
385
398
411
425
438
442
443
446
448 34
256
272
333
396
409
423
437
451
466
469
471
474
476 36
271
288
352
419
433
448
462
477
493
497
499
502
504 38
286
304
372
442
457
473
488
503
520
524
527
530
532 40
302
320
392
465
484
498
514
530
548
552
555
558
560 42
317
336
411
489
506
523
540
557
575
580
582
585
588 44
332
352
431
512
530
548
556
584
603
607
610
613
616 46
347
368
450
535
554
573
592
611
630
635
638
641
644 48
362
384
470
558
578
598
618
637
657
662
666
669
672 50
377
400
490
581
602
623
644
665
685
690
694
697
700 52
393
416
509
605
626
648
669
692
711
718
721
724
728 54
408
432
529
628
650
673
695
718
740
745
749
752
756 56
423
448
548
651
674
698
720
745
767
772
776
780
784 58
438
464
568
674
698
723
746
772
794
800
804
808
812 60
453
480
588
697
722
748
772
798
822
828
832
836
840 62
496
607
719
746
772
797
824
849
856
859
864
864
868 64
483
512
627
742
770
797
823
851
877
883
887
862
896 66
498
528
646
766
794
822
849
877
904
911
915
920
924 68
513
544
666
790
818
847
875
904
931
939
943
948
954 70
528
560
686
814
843
872
901
930
959
966
971
976
980 72
544
576
705
838
867
896
926
956
986
994
998
1004
1008 74
558
592
725
861
891
921
951
982
1014
1021
1026
1032
1036 76
573
608
745
884
915
946
977
1008
1041
1049
1054
1060
1064 78
588
624
765
907
939
971
1002
1034
1068
1076
1082
1088
1092 80
604
640
785
930
964
996
1028
1060
1096
1104
1110
1116
1120 --+----+----+----+----+----+----+----+----+----+----+----+----+----
In urines containing pus, the clear portion should always be examined for alb.u.men, since where this is found, except in small amount, some form of kidney disease may be suspected.
But it sometimes happens that the pus is present in such small quant.i.ty in the urine as to preclude its chemical examination. Under these circ.u.mstances, recourse must be had to the microscope. Dr Lionel Beale says, "Pus-globules, which have been long removed from the body, always have a granulated appearance in the microscope, and, when fresh, do not always exhibit a well-defined nucleus; the outline is usually distinct and circular, but it is finely crenated. Upon the addition of acetic acid the globule increases somewhat in size, becomes spherical, with a smooth, faint outline, and from one to four nearly circular bodies are developed in the centre of each. If the pus-corpuscles have lain some days in the urine they will have undergone complete disintegration."
_Epithelium._ A great many varieties of epithelium, derived from different parts of the kidneys, ureters, bladder, urethra, v.a.g.i.n.a, &c., are more or less present in urine. A few of these are given in the accompanying engraving. In the various diseases peculiar to the urinary and genito-urinary organs the quant.i.ty of epithelium present in the urine is frequently considerable, and as in some cases it presents itself in an imperfect or disintegrated form, its identification, except to the experienced microscopist and physiologist, becomes a matter of great difficulty.
_Casts._ Casts or moulds which have been formed in the tubes of the kidneys, or in the uterus and v.a.g.i.n.a, are constantly finding their way into the urine of persons affected with acute or chronic renal diseases and uterine affections. They are very varied both in character and appearance, and difficult of recognition, except by the skilled microscopist and pathologist.
_Blood-corpuscles._ These, when present in quiescent urine, occur as a sediment at the bottom of the vessel. Some few globules, however, are diffused throughout the supernatant urine, and impart to it a smoky appearance, if the fluid have a marked acid reaction; whereas if the reaction be alkaline the corpuscles a.s.sume a bright red colour.
In the accompanying plate the three upper groups represent blood-corpuscles taken from the human body; the three lower those found in urine. Of these latter some will be seen to have lost their circular outline, and to have become jagged or crenated. In some cases, on the contrary, they swell and become much enlarged. These changes in appearance take place when the blood has remained for some time in the urine, and appear to be due to the forces of endosmose and exosmose.
[Ill.u.s.tration: (Beale.)]
_Fungi._ The chief vegetable organisms found in urine are the _sugar fungus_ and the _Penicillium glauc.u.m_. The sugar fungus is precisely the same as the yeast plant (the _Torula cerevisiae_). The _Penicillium_ is very frequently present in alb.u.minous urine, with an acid reaction, as well as in diabetic.
_Uric acid._ See back.
_Urates._--According to Bence Jones the soluble urates met with in healthy urine consist of uric acid, pota.s.sium, ammonium, and sodium.
In abnormal urine the urates of ammonium and sodium sometimes occur, the latter, which are the more general, presenting under the microscope the appearance shown below.
[Ill.u.s.tration: (Beale.)]
Urate of sodium is, however, much more common in the urine of children than of adults, when it presents itself in the form of spherical crystals.
In both cases the urates are a.s.sociated with uric acid (resulting from their partial decomposition), represented by the small spiked crystals protruding from the spheres in the form of needle-shaped crystals. Urate of sodium occurs as the concretions known as 'chalk stones' in gout. But by far the most abundant kind of urates met with in abnormal urine is that known as _amorphous urates_, which const.i.tute the most common variety of urinary deposits.
[Ill.u.s.tration: Urate of soda in a globular form commonly found in the urine of children.]
Heintz states that they are a mixture of urate of sodium with small quant.i.ties of the urates of ammonium, lime, and magnesium. They are very frequently seen in the urine of persons in excellent health, in which, owing perhaps to too abundant or nitrogenous diet and an insufficiency of muscular exercise, being in excess, they are thrown down when the urine cools.
An excess of the amorphous urates in urine, like the presence of pus and phosphates, is indicated by the bulky precipitate more or less diffused throughout the vessel containing the urine. A very easy test will decide as to which of the three cla.s.ses of substances (if only one of them be present) the precipitate belongs. The supernatant fluid being decanted from the deposit, about an equal bulk of liquor pota.s.sae is added to the latter, when one of three results will ensue:
1. If it be _pus_, and become viscid, it will exhibit the qualities already mentioned under the description of that substance.
2. If _phosphates_, no alteration will ensue.
3. If _amorphous urate_, it will at once dissolve.
When amorphous urates are uniformly distributed throughout the urine they give it a milky appearance, which may sometimes lead to its being mistaken for _chylous_ urine, or urine throughout which fatty particles of chyle are diffused. This latter doubt, however, may be easily set at rest by gently heating it. If the turbidity is owing to the urate it will disappear; if to chyle it will remain.
If the amorphous urate be decomposed by a little hydrochloric acid, it will yield uric acid, easily recognised by its characteristic form under the microscope, or when treated with nitric acid and ammonia, will answer to the murexed test.
It sometimes happens that in testing an acid urine suspected to contain alb.u.men, the urine may contain so large an amount of uric acid in solution that, upon adding a drop of nitric acid to it, a bulky precipitate of uric acid, exactly resembling alb.u.men, is thrown down, and it may be erroneously regarded as this substance if examined under the microscope immediately upon its formation. Upon being allowed, however, to stand some time, and then placed under the microscope, the well-known crystals of the acid will reveal themselves.
In such urine no precipitate takes place when the liquid is heated, another essential feature in which it diverges from alb.u.men.
_Phosphates._--The urinary earthy phosphates occur under two varieties, viz. the phosphate of ammonia and magnesia, known as the triple phosphate, and the phosphate of lime.
In the engravings below, the princ.i.p.al crystalline forms of the triple phosphate are shown.
[Ill.u.s.tration: FIG. 1.--Crystals of triple phosphate with spherules of urate of soda. (Beale.)]
[Ill.u.s.tration: FIG. 2.--Crystals of triple phosphate with triangular prisms, with truncated extremities. (Beale.)]
Of these the triangular prismatic, with the truncated extremities, is the most common. In some cases the prisms are so much reduced in length as to resemble the octahedral crystals of oxalate of lime, for which they are sometimes mistaken by the inexperienced. When any doubt exists on this point it must be set at rest by having recourse to the chemical tests given further on. The triple phosphate is rarely met with alone, urate of ammonia, and sometimes uric acid and oxalate of lime, being present, although generally occurring in neutral or alkaline urine. The triple acid is sometimes found in that which is acid.
When ammonia is added to fresh urine the triple phosphate is precipitated, and if it be then examined by the microscope it will be found to consist of beautiful stellate crystals, and to form a most attractive object. The presence of phosphoric acid can be demonstrated by the ordinary reagents.
Phosphate of lime dissolves in strong acids without effervescence. The presence of lime, as well as of phosphoric acid, can easily be verified by the usual tests.
_Oxalate of lime._ The princ.i.p.al crystalline forms of oxalate of lime, when it occurs as a urinary deposit, are the octahedral and the dumb-bell.
Of these the most common is the octahedral. These octahedra (which have one axis much shorter than the other two) vary considerably in size, but there is reason to believe that the diversity in appearance which they exhibit is due to crystals of precisely the same shape occupying different positions as to the direction of their axes, when examined by the microscope. There are a great many diversities of the dumb-bell form of oxalate of lime, which seem to be derived from circular and oval crystals. The subjoined cuts ill.u.s.trate the varieties of crystalline oxalates the most generally met with. When the crystals of oxalate are extremely minute, they are very liable to be overlooked, since they then appear as almost opaque cubes, and may not unnaturally be taken for urate of soda, to which they bear no slight resemblance; but from which they differ by being insoluble in potash or acetic acid, and not dissolving on the application of heat. We have already alluded to their resemblance to the dumb-bells of the earthy phosphates. Another distinctive feature is that the oxalates rarely sink to the bottom of the vessel, but are diffused through the mucous cloud, which forms in urine after a short time.
