Charles D. F. (Charles Douglas Fergusson) Phillips.

Materia medica and therapeutics, inorganic substances; (Volume 2) online

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The liquid is then concentrated to crystallization.

CHARACTERS. Occurs in small granular crystals, deliquescent, soluble,
neutral in reaction, and somewhat bitter in taste.

POTASS^E TARTRAS ACID A ACID TARTRATE OF POTASH CREAM
OF TARTAR, KHC 4 H 4 O 6 ,=188.

PREPARATION. Grape-juice contains a large quantity of this salt,
which is retained in solution by the saccharine matter. When this latter
is converted into alcohol by fermentation, the acid tartrate is gradually
deposited inside the wine casks, and is known as " crude tartar," or
" argol," and this, when purified by recrystallization, constitutes " cream
of tartar," a name originally given to the fine crystals which were " skim-
med off " the evaporating liquid.



266 MATERIA MEDICA AND THERAPEUTICS.

CHARACTERS AND TESTS. Occurs as a gritty white powder, or in
fragments of cakes. It is distinguished from the neutral tartrate by its
very sparing solubility in water, viz., 1 in 180 parts: in spirit it is in-
soluble, like other tartrates. It chars on exposure to heat, giving off in-
flammable gas and an odor of burnt sugar.



POTASS^ SULPHAS SULPHATE OF POTASH, K 3 SO,=174.

PREPARATION. There is no process directed in the Pharmacopoaia,
but the salt may be prepared from the residue left in the manufacture of
nitric acid, this residue being an impure acid sulphate, which is converted
into the neutral salt by treatment with lime, and afterward with carbon-
ate of potash and sulphuric acid.

CHARACTERS AND TESTS. A very hard crystalline salt, sparingly
soluble in cold water; decrepitates on heating: has a bitter, rather nau-
seous taste.



POTASSA SULPHURATA- SULPHURATED POTASH (HEPAR SUL-

PHURIS).

PREPARATION. By fusing together carbonate of .potassium and sub-
limed sulphur.

CHARACTERS AND TESTS. From its liver color, when fresh, it was
formerly called " liver of sulphur," but it rapidly absorbs oxygen from
the air and becomes green, and ultimately dull white, sulphate of potash
being formed. It evolves sulphuretted hydrogen on the addition of any
acid.



POTASS^ N1TRAS NITRATE OF POTASH NITRE SALTPETRE, KNO,,

=101.

PREPARATION. Nitrates occur naturally in many waters, soils, and
plants, but are mainly obtained either from certain soils in India by solu-
tion in water, or from artificial " nitre beds," i.e., heaps of manure and
vegetable refuse, wood ashes and calcareous earth, which are exposed to
the action of air and sun. The nitrogen of the organic matter .is slowly
oxidized into nitric acid, which combines with the bases present (potash,
etc.), and the nitrates so formed are removed by washing.

CHARACTERS AND TESTS. Occurs in white crystalline fragments, or in
striated, long, six-sided prisms, which are transparent. It is soluble in
water, and has a cooling taste; at a red heat it deflagrates. When fused
and cast into round moulds, it is known as " sal prunelle;" abroad, these
are often colored purple (like a plum: prunelle a sloe).



POTASSIUM. 267



POTASS^ CHLORAS CHLORATE OF POTASH, KC1O 8 , =122.5.

PREPARATION. By passing chlorine gas over a mixture of potash car-
bonate and excess of slaked lirne; chlorinated lime and chlorinated potash
are first formed, and the latter is then converted into chlorate of potash
on boiling; but the reaction may be simply expressed thus

6Cl a + K 2 CO 3 + 6CaH 8 O 2 = 2KC1O S + CaC0 3 + 5CaCl 2 + 6H,O.

CHARACTERS AND TESTS. Chlorate of potash occurs in pearly-white,
hard, crystalline plates, which are slightly soluble in water, and have a
cooling taste. Rubbed with sulphur, or phosphorus, or tannic acid, or
catechu, etc., the salt explodes; treated with sulphuric acid, it becomes
red, and gives off vapors of chlorine peroxide.



POTASS^E PERMANGANAS PERMANGANATE OF POTASH, KMnO 4 ,=

158.

PREPARATION. The principal steps of the process are (1 ) to prepare
manganate of potassium (K 2 MnO 4 ); (2) to convert this into permanga-
nate (KMnOJ by boiling. Black oxide of manganese, caustic potash, and
potassic chlorate are fused together, and a dark green mass of manganate
of potash obtained.

3MnO,+6KHO + KClO,=3K a MnO 4 + KCl+3H a O.

This manganate, when boiled, filtered, and acidified with sulphuric acid,
yields a purple solution of the permanganate.

3K,MnO 4 + 2H 2 O = 2KMnO 4 + 4KHO + MnO 2 .

The green manganate, when turning into the purple permanganate, under-
goes several changes of color, and hence has received the name, " mineral
chameleon:" finally, the solution is evaporated, and the crystals purified.

CHARACTERS AND TESTS. Occurs in dark purple acicular crystals,
one of which will impart its color to a large quantity of water. It yields
up most of its oxygen (five-eighths) very readily; and if only a little
spirit be boiled with its solution, it changes to yellowish brown, on ac-
count of its reduction to the state of peroxide. A similar brown stain is
left on the hands when washed in it, on account of its oxidation from
contact with the organic substance. In distilled water, the purple color
may remain two years without change. (Manganese stains are removed
by oxalic acid " salts of lemon.")

POTASSES BICHROMAS BICHROMATE OF POTASH, K a Cr 2 O 7 ,=295.

PREPARATION. By roasting chrome iron-ore with a mixture of car-
bonate of potash and chalk; yellow chromate of potash is formed, and
yields the red bichromate when treated with sulphuric acid.



268 AIATERIA MEDICA AND THERAPEUTICS.

CHARACTERS AND TESTS. Occurs in large, red, transparent, four-
sided tables, soluble in ten times their weight of water. The solution
readily gives up part of its oxygen, and when acidified with sulphuric
acid, turns green from reduction of the chromic acid, and formation of
green sulphate of chromium.

ABSORPTION AND ELIMINATION. Liquor potasses, taken on an empty
stomach, is quickly absorbed; it then combines, probably, with carbonic
acid in the blood, and is eliminated by the kidneys, mainly in combina-
tion with sulphuric acid (Parkes: Medico- Chirurgical Review, 1853).
When taken with food, or in very small doses at any time, it forms with
the gastric acid a chloride, and as such is absorbed; its elimination under
these conditions is not recognized so readily.

The carbonates, when taken in small doses, are absorbed as chlorides;
of large doses, the greater part passes out by the kidneys unchanged:
a single large dose (2 dr.) is eliminated more quickly than the same
amount given in divided doses (Thompson: Medico- Chirurgical Review,
ii., 1864). The acetate and citrate are reduced in the system to carbonate,
and eliminated as such; the tartrate is commonly unchanged. The chlo-
ride, chlorate, and nitrate are absorbed very rapidly, and have been de-
tected in the urine, the saliva, etc., within five minutes after being taken.

Much interest attaches to the chemical changes which the chlorate
undergoes in the system; it was believed to become a chloride, parting
with its oxygen to the blood and tissues (Fourcroy) the proportion even
of oxygen furnished was calculated (Garnett). Gubler and some other
modern observers also think it possible that a partial reduction of the
salt may occur within the body, but it is difficult to reconcile this with
the chemical fact of its being found unchanged in the urine passed after
its administration (Wohler, 1824), as also in the saliva, milk, tears, bron-
chial mucus, etc. (Isambert). Rabuteau, taking himself small doses, also
found the drug imchanged in the secretions, and of one large dose of 5
grammes, recovered 4.873 grammes from the urine within thirty-six hours
( Gazette Med. de Paris, 1868). Hence it seems improbable that the chlor-
ate should decompose and give up oxygen at the temperature of the body,
and yet there is some clinical evidence of its improving oxygenation in
whatever mode this may be effected (v. vol. i., p. 19, and vol. ii., p. 282).

When nitrate of potash has been taken in large doses (270 gr. in
twenty-four hours), the greater part has been found unchanged in the
urine the rest probably passing as sulphate by the intestines (Taylor:
Guy's Reports, 1863); that a certain amount of potash salt passes off in
this manner has been shown by Kramer (Annales d'Hygiene, i., 1843).

PHYSIOLOGICAL ACTION, Oxidation and Nutrition. How far alka-
lies, as such, contribute to oxidation, has long been a question of interest,
and it is one of great practical importance. Organic substances, such as
bile and haernatin, when exposed to air outside the body, certainly oxidize



POTASSIUM. 269

more quickly when in contact with potash (Chevreul, 1825) : olein, again,
is not acted on by ozone alone, but if potash be added, oxidation sets in
at once. We know, also, that albumen, dissolved in water, changes but
slowly, while the addition of alkali induces immediate oxidation, and in
the ordinary test for diabetic sugar, potash deprives of oxygen even a
metallic oxide.

Physiological chemists did not fail to trace a similar action within the
body. Lehmann and Mialhe taught that alkalies were powerful promot-
ers of systemic oxidation, and augmented the excretion of urea arid car-
bonic acid. Liebig fully adopted the same view, teaching that they pro-
moted the combustion of " respiratory foods," and pointing out that if
organic acids (gallic, citric, etc.) were taken alone, they passed off almost
wholly unchanged, but if in combination with alkalies, e.g., as citrate of
potash, the acid was " burnt off " in the system, and the alkali passed as
a carbonate. The experiments of Frerichs illustrated the same point; he
gave urate of potash to rabbits, and yet found no uric acid in the urine,
for it became changed into oxalic acid and urea, the excretion of the lat-
ter being much increased.

Bence Jones concluded that alkalies, though they could not themselves
give up oxygen, decidedly assisted oxidation of organic substances within
the body by promoting the formation of acids (" Lectures," and Lancet,
i., 1867, p. 202), and Parkes found, in a series of analyses, that the or-
ganic material and sulphuric acid excreted in the urine were markedly
increased under the use of liquor potassae, which acted, he considered, by
increasing the oxidation of sulphur and protein tissues; for this effect it
had to be given at least eight hours after food ( Medico- Chirurgical Re-
view, 1853). Similar results did not follow the use of acetate or nitrate
of potash in Parkes's experiments, but Dr. Golding Bird reported a con-
siderable increase of urea and other urinary solids in the case of a dog
submitted to the action of 3 dr. of the acetate (" On Urinary Deposits").
Dr. Reginald Thompson proved by several series of observations, that the
amount of\ phosphoric acid in urine was increased by the administration
of carbonate of potash (Medico- Chirurgical Review, ii., 1864).

Besides the cases reported by Dr. Parkes, we have clinical evidence
from Dr. Austin Flint of much increase in the urinary solids of a number
of patients taking nitrate of potash, and Dr. Basham, observing specially
cases of lithic acid diathesis, not only found the urea increased under the
use of potash, but oxalic acid appeared as uric acid lessened, and oxalic
acid and urea are recognized products of the oxidation of uric acid.

We might almost conclude from the preceding statements that the
question as to alkalies increasing oxidation was answered in the affirma-
tive, and yet practical experience shows that some qualifying statement
is required, for do we not see marked asthenia, pallor, and anaemia pro-
duced in many persons by full doses of alkali, and in all persons by their



270 MATERIA MEDIC A AND THERAPEUTICS.

continued use ? (so that Trousseau speaks of their doing more harm than
the abuse of iodine or mercury); and moreover, is not temperature re-
duced by salts of potash, so that they are used as anti-pyretics ? whereas,
if they increased oxidation, the results should be opposite to these. (Dr.
Ridge argues that although some amount of alkali promotes oxidation,
the "secondary effect "is to retard it Medical Times, ii., 1871.) To
advance knowledge in this direction, Rabuteau has recently recorded the
results obtained on himself, on Constant (of Smyrna), and on a third per-
son (a woman). Each took 5 to 6 grammes of bicarbonate of soda or pot-
ash for five to ten days. The full dose of bicarbonate of potash produced
a slight diuretic effect, but 5 grammes none at all; urea was markedly
and progressively diminished, and depression and anaemia were induced:
analogous results were obtained by Ritter, of Nancy; 5 grammes of chlo-
rate equally diminished urea (Fouilhoux, These, Paris, 1874), and 10-
gramme doses of nitrate acted in a similar manner (Jovitzu).

The explanation of such contradictory results turns largely upon the
question of dosage, as with many other medicines. Large quantities,
like those last referred to, will pass out unchanged and quickly, and in
their passage so far deteriorate the blood-condition and impair the func-
tion of the alimentary tract as to induce asthenia and diminish nutrition;
hence, evidently Dr. Parkes's supposition that increasing the dose of
potash will proportionately increase oxidation cannot be sustained. Small
doses* on the other hand, not only help to saponify fatty food, but aid its
oxidation, and that of carbonaceous material generally, improve the di-
gestion, and raise the temperature.

Rabuteau himself confirms these statements, and explains these effects
of small doses by their change into chloride in the stomach, and their
acting as chlorides rather than as alkalies; under the influence of 5-
gramme doses of chloride of potassium he found the excretion of urea
increased by 20 per cent.

That potash salts are essential for the development of the animal tis-
sues is shown by the fact that food which in itself is not sufficiently nu-
tritious, such as over-stewed meat, recovers its properties on the addition
of these salts and of a little sodium chloride (Binz); the absence of
potash salts seems to be at least one cause of scurvy (Garrod). If, on
the other hand, we give meat broth which is very rich in potash salts,
without adding any other nutrient, tissue-change becomes so acceler-
ated that animals thus fed die earlier than others kept without food.

Experiments with plants show also how necessary potassium is for
cell-nutrition; if it be excluded from their soil and water no growth
takes place, for without its presence in the chlorophyll granules no starch
is produced.

Souligoux, in a recent treatise, emphasizes the necessity of a due
amount of alkali for carrying on all the vital processes, and brings evi-



POTASSIUM. 271

. i

dence to show that a large part of its good effect lies in its favoring
proper electrical reactions and currents within the organism (" Etude sur
les Alcalins," 1878, Paris).

Circulatory System. A certain amount of potash salt is essential, as
we have seen, for the proper constitution and action of the corpuscles,
and the chloride seems to be the best suited for this purpose (Rabuteau);
but the prolonged use of the remedy in any combination has an unfavor-
able effect. Loffler has reported the results in five of his students who
took doses of from 1 to 5 dr. of alkaline carbonates for several days, and
then allowed blood to be taken from a vein. It was found to be like
" cherry juice " in color and density, the red corpuscles were paler, and
the white ones more numerous than normal; there was excess of water
and of fatty material, and the clot was less firm and elastic than it ought
to be (Schmidt's Jahrb., 1848). A curious illustration of the diminished
coagulating power of the blood under the influence of nitrate of potash
is furnished by Dr. Stevens, who had occasion to bleed a man who had
lately taken an ounce of that salt, and was surprised to find the venous
blood red, and not at all coagulable (Lancet, ii., 1862, quoted by Dr.
Basham). In animals, after injection of nitrate, the result is similar
(Rabuteau).

Martin Solon, having analyzed blood drawn from the vein of a robust
man suffering from acute rheumatism, and treated by nitre, found the
fibrine diminished, though the inflammatory process was still ' at its
height; ten days afterward, when the remedy was no longer being taken,
the blood-clot was dense and buffed (Bulletin de Therapeutique, 1843).
That the drug cannot, however, be depended upon for antagonizing the
effects of disease is shown by the fact of fibrinous deposits having been
found on the heart-valves in patients dying during its free administration
(Medical Times, i., 1863).

Both this salt and the chlorate have the power of rendering venous
blood bright red, and much stress was laid upon this change by the early
advocates of the direct oxygenation theory (Stevens, O'Shaughnessy :
Lancet, ii., 1831), but Isambert, after making fresh experiments, asserts
that their statements on this point are incorrect ( Gazette Med., 1874), and
although the change does occur, it varies with physical conditions, and
is dependent rather on altered osmosis than on difference in oxygenation.

Small doses of the potassium salts (excepting the permanganate) cause
a fall in the pulse-rate, but a rise in the arterial pressure, probably through
the vaso-motor nerves; this effect is usually only temporary (Aubert,
Dehn). Full doses lower both pulse-rate and blood-pressure. The low-
ered pressure may, or may not, be followed by a rise according to the
dose employed. Parkes found a full dose of liquor potasses render the
pulse small and slow, but a copious secretion of urine explained this effect.
Under the nitrate the pulse-frequency came down in a few days from 70



272 MATEEIA MEDIOA AND THERAPEUTICS.

to G4 (Rabuteau, p. 229), and the chlorate, according to Socquet, of
Lyons, has a similar sedative action. Some observers report a quickened
circulation, especially after venous injection of chlorate (Gubler) ; Jacobi
speaks of this salt congesting the kidney (Medical Times, i., 1876), and
Osborn of its congesting the brain (Lancet, ii., 1859); but such effects
must be exceptional. The observations of Black (1839), and of Bouchar-
dat (1844), and the experiments of Podocsepow (Virchow's Archiv, Bd.
xxxiii., p. 505), of Guttman, Aubert, Dehn, and others agree in assigning
to potash salts a distinctively depressing effect on the heart-action. Their
injection in frogs quickly lessens the force of the blood-current, and finally
arrests the heart in diastole: 10 gr. of chloride injected into the jugular
vein of the smaller animals cause instant cardiac death, and since the
heart-muscle in such cases is found insensitive to electricity (Traube), and
since previous section of the vagi has no influence on the result, we con-
clude that the cardiac arrest is due to a direct paralysis of the muscu-
lar substance. This paralysis is commonly preceded by increased activity,
but finally it becomes complete, so that the heart-muscle ceases to react
to any ordinary stimulus. If, however, the potash chloride be introduced
gradually into the system through the stomach, then cardiac contractility
is not entirely destroyed by it.

The bitartrate of potash has some power of arresting hemorrhage, es-
pecially from the kidney (Ramskill and others, Ranking, i., 1867); it pos-
sibly lessens congestion by diuresis or purgation. Albuminuria has oc-
curred under the influence of nitrate.

Nervo-Mitscular System. Large doses of potassium salts lower the
reflex irritability of certain parts of the spinal cord (Binz), but many
observers consider this to be only secondary to depression of the circula-
tion. The fall of temperature adduced is attributed to the same cause.
In warm-blooded animals motor power is weakened, probably from a
direct alteration in the chemical constitution of muscular elements, for
electrical reaction remains. (On the other hand, Ramskill finds baths of
sulphuret of potassium to be the most effective stimulant to muscular ac-
tion during such diseases as wasting palsy Medical Times, ii., 1860.)
In healthy men a sense of weight and fatigue is often felt in the limbs
after absorption of the more easily diffusible salts, as the nitrate, oxalate,.
chloride, iodide, or bromide; local anaesthesia of various parts of the body
has been described as a result of drachm doses of bicarbonate (British
Medical Journal, ii., 1876). There seems, however, to be some idiosyn-
crasy with regard to such effects, and although full doses usually depress
the nerve-functions, Dr. Prout refers to pronounced nerve-excitement,
and even convulsion in some cases, as connected with an excess of alkali,
and the chlorate of potash is said to have caused headache and cerebral
congestion (u. p. 272). Isambert considered it a nervine sedative, but
" this action was not evident in healthy persons " {Medical Times, it,.



POTASSIUM. 273

1856). Rabuteau finds the "perchlorate " to produce giddiness and other
symptoms like those of quinine. Liquor potassas has been used to quiet
the spasms of tetanus (Lancet, i., 1861).

Dr. Thompson traces the nerve-depression commonly caused by alka-
lies to an increased excretion of phosphoric acid under their use (v. p. 269).

Glandular System Mucous Membranes. Dilute alkaline solutions
taken into the stomach before meals augment the secretion of gastric
juice (Blondlot, C. Bernard), for if digestion is to continue, fresh secre-
tion must occur to compensate for what is neutralized; also the chlorides
that are formed augment the secretion (Rabuteau). " They favor the
outward osmosis of those constituents of the blood from which the acid
of the stomach is elaborated " (Bartholow). But alkalies given in too
large or too concentrated a dose arrest the secretion, and if given soon
after a meal prevent even a normal amount of acidity. Dr. Ringer for-
mulates a general proposition thus: "Alkalies applied to the orifices of
glands with acid secretions increase their secreting power, while alkalies
applied in a corresponding way to glands with alkaline secretion lessen or
check this secretion;" and I think that, as a general rule, and with due
regard to the strength of solution, this may be held true.

The increased secretion of saliva caused by direct application of
alkalies is thick, whitish, and cloudy; it is not large in amount, and there
is some doubt as to whether it is true secretion or (as Kiibne thinks) the
result of a rapid degeneration of the gland. A similar fluid results from
irritation of the sympathetic nerves of the submaxillary gland, and hence
the alkali has been thought to act through the sympathetic. The chlorate
of potash sometimes acts so as to produce a degree of salivation.

Under the influence of alkalies taken internally, the bile and pancrea-
tic juice are increased in amount, and rendered more fluid. The sulphate
of potash given internally has special power in this direction (Rutherford),
more than magnesia. The bronchial secretions are also increased and
fluidified by alkalies, and the movements of ciliated epithelium are
rendered more active by them.

Secretion from the intestinal glands is augmented, especially by full
doses of the potash salts of mineral acids: 2 or 3 dr., e.g., of the sulphate
cause watery purging; larger quantities sometimes irritate much: -oz.
doses have been used in France as abortifacient with serious effects (Mow-
bray), and 2 oz. have caused death (Taylor).

The nitrate in small doses is absorbed and produces some constipation,
but in full doses and well diluted causes diarrhoaa (Martin Solon, 1843).
Orfila reported violent irritation of the mucous membrane from its use,
and an ounce has caused death with irritant symptoms and depression,
though this is exceptional. The experiments of Rognetta indicated only a
moderate degree of congestion no inflammation; and ounce doses, when
well diluted, have been given medicinally without serious result.
VOL. II. 18



274 MATERIA MEDIC A AND THERAPEUTICS.

The chlorate may also irritate mucous membranes, and in large doses
has sometimes, though rarely, caused death through this effect, e.g., in a
patient with phthisis, who took 300 gr. daily for four days, and in the
case of Dr. Fountain, who unfortunately took an ounce in order to orove
his conviction of its innocent character (Stille).

The bichromate in small doses increases all the secretions, in large
doses acts as an irritant poison, and induces suppression of urine.

The urine is often markedly increased in quantity by liquor potassae
(Parkes), by the bicarbonate and the chlorate, but still more by the bitar-
trate, nitrate, acetate, and citrate; the increase is not always decided,



Online LibraryCharles D. F. (Charles Douglas Fergusson) PhillipsMateria medica and therapeutics, inorganic substances; (Volume 2) → online text (page 33 of 40)