Cooley's Cyclopaedia of Practical Receipts 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.