permanganate to pyridin tricarboxylic acid, oxalic acid, and
ammonia (M. & M., iv. 375). 12. With resorcin a solution of
quinine sulphate or bisulphate a precipitate is formed. 13.
Quinine bisulphate in sunlight turns yellow and then brown-
14. When qumine sulphate is rubbed with phenol or
thymol is gives a soft mass; with chloral hydrate it gives a
damp powder or stiflF mass. 15. The solubility of qumme sul-
phate in water is increased by the presence of certain compounds,
as ammonium chloride, potassium nitrate, and antipyrine.
Reslna. — i. Pine resin when triturated with menthol,
salol, carbolic add, or ure thane makes a liquid or sticky
mass. 2. Nitric add oxidizes it to isophthalic and trimellitic
acids (M. & M., i. i). 3. Potassium permanganate oxi-
dizes it to formic, acetic, and carbonic acids (M. & M., i. i).
Besinse. — i. With aqueous solutions of alkali hydroxides
or carbonates resins form resin soaps which are generally sol-
uble in water, 2. Nitric acid converts them into artificial
INCOMPATIBILITIES IN PRESCRIPTIONS, 109
tannin (U. S. D., 1150). 3. Concentrated sulphuric acid
dissolves many of the resins with decomposition and gives
color reactions with some. 4. Tincture of ferric chloride
gives different colors with resinous substances. [See Ferri-
CUM, No. 26.3 5. Alcohol containing hydrochloric acid is
colored red to violet by myrrh ; yellowish brown to green by
guaiac; yellow, changing through brown to cherry-red, by
benzoin or balsam of Tolu ; greenish, changing to dingy vio-
let, by asafcetida; and brown by some other resins. 6. Alcoholic
solutions of resins, as tincture of myrrh or benzoin when mixed
with water give precipitates that generally adhere to the bottle
or agglutinate, particularly if there is a metallic salt dissolved
in the water. Honey helps to suspend the resin and keep it
from sticking. About one dram of honey to seven drams of
the aqueous solution makes a presentable mixture.
Resorcinol. — i. An aqueous solution exposed to the air
becomes red and brown. This reaction is hastened by the
presence of alkalies. 2. With a dilute solution of ferric chlo-
ride resorcin gives a violet coloration. 3. With chlorinated
lime or soda a solution of resorcin gives a violet coloration
changing to yellow. 4. Nitrous acid or spirit of nitrous
ether gives a dark red solution with resorcin. 5. A solution of
quinine sulphate or bisulphate is precipitated by it and the fluo-
rescence is destroyed. 6. Resorcin produces a liquid or soft
mass when triturated with many solids. [See page 267.]
Saccharam. — i. A solution of sugar heated with lime,
magnesia, litharge, and other metallic oxides and hydroxides
form saccharates, chemical compoimds which are more or less
soluble in water. 2. The presence of sugar hinders or pre-
vents the precipitation, . or dissolves the precipitate, of many
metallic hydroxides or oxides which are normally formed when
alkali hydroxides are added to solutions of metallic salts. The
interference is most marked, in case of lead, antimony, cop-
per, mercuric, ferrous, ferric, aluminum, zinc, calcium,
and magnesium salts. 3. Very strong nitric acid with sugar,
in the cold, forms explosive nitrosaccharose (Allen, i. 270).
no INCOMPAT/BILITIES IN PRESCRIPTIONS.
Moderately concentrated nitric acid converts sugar into sac-
charic and tartaric acids, and with heat into oxalic acid and
carbon dioxide (Allen, i. 270). 4. With concentrated sulphuric
acid sugar is decomposed, forming carbon, while formic acid,
sulphur dioxide, and other gases are given ofiF (Allen, i. 271).
5. Sugar warmed with dilute solution of acids, or heated for
some time with water is changed to invert-sugar. 6. When a
concentrated solution of sugar and potassium hydroxide is
heated, carbon dioxide, acetone, acetic, propionic, and oxalic
acids are formed (M, & M., iv. 551). 7. Sugar combines with
sodiiun chloride, forming deliquescent crystals (N. S. D., 1340).
8. Chlorine or bromine oxidizes sugar to gluconic acid, glu-
cose and other products. The same reaction takes place in the
presence of lead or silver oxide (M. & M., iv. 551). 9. Iodine
with potassiimi carbonate and sugar yields a little iodoform
(M. & M., rv. 551). lodme is converted into hydriodic acid by
heating with a solution of sugar (N. S. D., 1340). 10. Dilute
chromic acid solution oxidizes sugar to oxalic, formic, and
carbonic acids (M. & M., iv. 551). 11. Potassium perman-
ganate converts sugar into oxalic, formic, and carbonic acids
(M. & M., IV. 551). 12. Sugar triturated with potassium
chlorate, permanganate, or bichromate, or with other strong
oxidizing agents, is liable to cause an explosion. 13. Syrup of
hydriodic acid or ferrous iodide sometimes slowly turns brown,
due to the action of the acid or iodide on the sugar. 14. Exposed
to the light it slowly changes into glucose (N. S. D., 1075). 15.
Sugar renders the fixed and volatile oils to a certain extent
miscible with water and forms with them an imperfect com-
bination (N. S. D., 1074).
Saccharum Lactis. — i. Milk-sugar in alkaline solution
reduces salts of copper. 2. Nitric acid first inverts milk-
sugar and then forms mucic and saccharic acids, and if heated
forms tartaric and racemic acids and finally oxalic acid. 3.
Dilute acids mvert milk-sugar, forming dextrose and galactose.
4. A mixture of sulphuric and nitric acids with milk-sugar gives
lactose pentanitrate, which is explosive (M. & M., iv. 553)
INCOMPATIBILITIES IN PRESCRIPTIONS. Ill
5. Chromic acid with milk-sugar yields aldehyde (M, & M., iv.
553). 6. Alkali permanganates oxidize milk-sugar. 7. Silver
oxide oxidizes it^ forming oxalic, glycollic, and lactonic acids
(M. & M,, IV. 553).* 8. Milk-sugar with a solution of iodine
and sodium bicarbonate yields a little iodoform (M. & M.,
IV. 553). 9. Triturated with oxidizing agents, it is liable to
cause an explosion.
Salacetol. — i. Salicyl-acetol is decomposed by alkali
hydroxides, forming a salicylate.
Salicinuiii. — i. Salicin is not readily precipitated by any
of the common precipitants. 2. Dilute acids and water with
heat change it to glucose and saligenin.
Salophen. — i. Salophen dissolves in solutions of potas-
sium or sodium hydroxide but is decomposed by them. Boil-
ing the sodium hydroxide solution a blue color is developed,
beginning at the top (N. S. D., 1165). 2. Tincture of ferric
chloride gives a brown-red to violet color.
Saloquinine. — i. Acids dissolve it. 2. From the acid
solutions, alkali hydroxides and carbonates and the general
alkaloidal reagents precipitate it. 3. With a very dilute solution
of ferric chloride, its alcoholic solution gives a reddish violet
Santonin. — i. Santonin on exposure to light turns
yellow, forming photo-santonic acid and a yellow-resinous
body (A. D., 1718). 2. With alkali hydroxides in solution
it forms santoninates, which are soluble in water. 3. An
aqueous solution of santoninate is precipitated by lead acetate
or lead subacetate as lead santoninate. It is also precipi-
tated by tannic acid, ferrous sulphate, copper sulphate,
chlorine water, and by acids if the solution of santoninate is
not too dilute. 4. Santonin is turned pink or red by potas-
sium hydroxides in the presence of alcohoL 5. Heated with
nitric acid, santonin forms carbon dioxide, succinic, oxalic,
and acetic acids (M. & M., iv. 429).
Sapo* — i. Aqueous solutions of soap are decomposed by
mineral acids, which combine with the base, liberating the
112 INCOMPATIBILITIES IN PRESCRIPTIONS.
free fat acid. 2. Aqueous solutions of metallic salts give
precipitates of metaUic oleates with soaps. 3. Soap is fre-
quently alkaline, and when so it makes a black mixture with
calomel, due to the mercurous oxide formed. 4, It may
precipitate hydroxides or oxides from solutions of metallic
Sodii Thlosulphas.— I. Sodium thiosulphate (hypo-
sulphite) in aqueous solution is decomposed by nearly all acids,
forming sulphur, and sulphurous acid. An aqueous solution of
the salt slowly forms sulphur and a sulphite. 2. Aqueous
solutions of thiosulphates are decomposed into hydrogen
sulphide and sulphuric acid when boiled (M. & M., iv. 705).
3. Sodium thiosulphate precipitates, as thiosulphates, solu-
tions of barium chloride, silver nitrate, lead acetate, and
mercurous nitrate. The precipitates are white, but those
of the last three salts turn black on standing, forming the
sulphide of the metal and sulphuric acid. 4. Sodium thio-
sulphate with a solution of ferric chloride gives a dark violet
color, due to ferric thiosulphate. The solution soon loses its
color because the salt formed changes to ferrous sulphate. 5. In
acid solution sodium hyposulphite reduces iodine to hydriodic
acid; 6. chlorates to chlorine and hydrochloric acid; 7.
chromates to chromic salts; 8. permanganates to manganic
salts; 9. arsenic compounds to arsenous. 10. Sodium thio-
sulphate forms soluble double thiosulphates with many metal-
lic salts. II. Solutions of sodium thiosulphate dissolve silver
iodide, silver bromide, silver chloride, mercuric iodide,
lead sulphate, lead iodide, and other salts (Watts, v. 630).
12. With calomel in the presence of moisture it gives a black
mixture. 13. In very dilute solutions it prevents the precipi-
tation of some of the alkaloids by gold chloride. It combines
with the gold to form a double thiosulphate. 14. An acidulated
solution bleaches vegetable colors on account of its reducing
properties. 15. When sodium thiosulphate is triturated with
potassium chlorate, nitrate, or permanganate, or other
strong oxidizing agents, explosion is liable to take place.
INCOMPATIBILITIES IN PRESCRIPTIONS. II3
16. Alcohol precipitates sodium thiosulphate from an aqueous
solution as an oily liquid (N. S. D., 1423). 17. Thiosulphates
are generally soluble except lead, silver, mercurous and lead.
Sozoiodol, Diiodoparaphenolsulphonic Acid. — i. An aque-
ous solution of sozoiodol gives a precipitate with silver nitrate
and lead acetate. 2. It gives a violet color with a solution of
ferric chloride. 3. It precipitates many of the alkaloidal
salts from aqueous solution. 4. Oxidizing agents Uberate
Spiritus. — ^Water causes a separation of the volatile sub-
stance from all of the official spirits except spirit of nitrous ether,
spirit of ammonia, whiskey, and brandy. They all contain
alcohol, and consequendy have the reactions of alcohoL
Strontiain. — i. Salts of strontium in aqueous solution are
precipitated by the soluble carbonates, phosphates, or oxa-
lates as strontium carbonate, phosphate, or oxalate. 2. The
soluble sulphates, chromates, or alkali hydroxides precipitate
from concentrated solutions the strontium sulphate, chromate,
Strychnina. — i. Strychnine combines with acids to
form salts. 2. Strychnine salts in aqueous solution are pre-
cipitated by the reagents mentioned under ALKALOIDS, Nos.
2 and 3. 3. In rather strong solutions of strychnine sulphate
the soluble chlorides, bromides, and especially the iodides
are liable to cause precipitation of the strychnine. The pre-
cipitation may not take place for several days. In explaining
the cause of the trouble several factors must be taken into
consideration. Frequently the commercial samples of the
alkali iodides and bromides are alkaline from the carbonate
which was left in to aid their keeping, and this alkali would
liberate and precipitate the strychnine. The compound which
potassium iodide forms with strychnine is only sparingly sol-
uble in water, but the corresponding compounds formed with
potassium chloride and bromide are more soluble. Some
writers partially explain the precipitation by saying that the
compounds formed are less soluble in water containing the
114 INCOMPATIBILITIES IN PRESCRIPTIONS.
inorganic salts than they are in water alone. Alcohol tends
to prevent the precipitation. 4. Hydrochloric acid added
to a solution of strychnine hydrochloride gives a crystalline
precipitate (M. & M., I v. 517). 5, Alkaline substances like
sodium phosphate, potassium cyanide, sodium arsenate,
Fowler's solution and piperazine will cause a precipitation
when added to an aqueous solution of a strychnine salt. 6. Pre-
cipitation by gold chloride is prevented to some extent by adding
to the gold chloride an equal weight of sodiiun thiosulphate.
[See AURI et Sodii Chlorodi, No. i.] 7. Strong nitric
acid if hot converts the alkaloid into the yellow explosive
compound which is probably the nitrate of nitrostrychnine
(Watts, V. 440). 8. One dram of dilute nitrohydrochloric
add with seven drams of water containing one fourth of a
grain of strychnine sulphate gives a yellow coloration in a few
days. In stronger solutions the change takes place more
quickly. The chemical products have not been definitely
determined. 9. Potassium permanganate in alkaline solu-
tion yields ammonia, oxalic acid, carbon dioxide, and another
crystalline acid, but in acid solution potassium permanganate
gives an amorphous acid with strychnine (M. & M., iv. 517).
Sulphonethylmethanmii, Trional. — i. Trional when
tritiurated with chloral hydrate, euphorin salol, thymol or
urethane gives a liquid or soft mass.
Salphonmethanam, Sul phonal. — i. Sulphonal is not
acted upon by alkalies, acids or oxidizing agents. 2. It liquefies
when tritiurated with chloral hydrate.
Sulphur. — Sulphur readily dissolves in hot aqueous solu-
tions of hydrates of potassium, sodium, barium, or cal-
cium, forming polysulphides and thiosulphates. 2. Tritiurated
dry with strong oxidizing agents, as potassium chlorate or
permanganate, explosion is liable to occur. 3. It combines
with most non-metallic elements.
Sulphuris lodidum. — i. Iodide of sulphur is decom-
posed by alcohol, ether, volatile oils, and solutions of potas-
sium hydroxide or iodide, the iodine being dissolved by these.
INCOMPATIBIUTIES IN PRESCRIPTIONS. II5
Terebenuin. — i. Terebene on exposure to air and light
resinifies and becomes acid. 2. It combines with chlorine,
bromine, and iodine to form additive products. 3. In many
reactions it resembles oil of turpentine.
Theobromina. — i. Thoebromine acts like a weak base,
and also like a weak acid. 2. It combines with strong acids
to form salts that are quite readily decomposed by water. 3.
It dissolves in an excess of an alkali hydroxide solution. 4.
From an aqueous solution, theobromine gives a crystalline pre-
cipitate widi silver nitrate, mercuric chloride, and gold
chloride. 5. With many of the general alkaloidal reagents
it gives no precipitate.
Thiol. — ^Thiol is precipitated from its aqueous solutions
by alkali hydroxides, mineral acids, and metallic salts.
Thymol. — i. Thymol unites with alkalies to form sol-
uble salts (U. S. D., 1250). 2. A solution of thymol with iodine
and potassium hydroxide gives a red amorphous precipitate of
iodothymol (M. & M., iv. 715). 3. Spirit of nitrous ether
gives a green and then a brown color, changing the thymol to
nitroso-thymoL 4. Thjrmol absorbs ammonia-gas and becomes
liquid (M. & M., iv. 715). 5. Thymol reduces gold and plat-
inum from solutions of their salts. 6. Chromic acid oxidizes
thymol to thymoquinone (M. & M., iv. 715). 7. Thymol gives
a liquid or soft mass when rubbed with aristochin, quinine sul-
phate, trional, and other solids. [See page 267.]
Thy molls lodldum, Aristol. — i. Aristol is decomposed
by light and heat, more quickly if dissolved in ether. 2. It
should not be prescribed with bodies that have a strong aflSnity
for iodine, as oxides, hydroxides, carbonates, starch, or
mercury salts. 3. Oxidizing agents h*berate iodine.
Tragacantha. — i. Tragacanth is colored yellow by a
solution of sodium hydroxide (Allen, l 428). 2. An aqueous
mixture is thickened by alcohol, and by neutral and basic
lead acetate (not coagulated by borax, silicates, or ferric salts)
(Allen, I. 428). 3. With water and bismuth subnitrate it
Il6 INCOMPATIBIUTISS IN PRESCRIPTIONS.
Urea. — ^Urea becomes soft or liquid when triturated widi
some solids . [See page 267J
Zinci Chloridum. — ^Zinc chloride, like gold and mer-
curic chlorides, has a strong tendency to combine with organic
bases, as strychnine, morphine, and quinine (U. S. D., 1352).
[See ZmcxJM and Acidum Hydrochlgricum.]
Zinci lodidom. — i. Conmiercial zmc iodide frequendy
does not give a clear solution with water. It is quite distincdy
alkaline to litmus and may give a further precipitate when mixed
with a solution of zinc chloride.
Zincum. — i. Zinc salts in aqueous solutions are precip-
itated by the fixed alkali hydroxides or lime water as zinc
hydroxide which is soluble m excess of the alkali hydroxide.
2. Zinc salts are precipitated by soluble carbonates, phosphates,
arsenates, or cyanides, as the basic carbonate, phosphate,
arsenate, or cyanide. 3. Borax gives a precipitate of zinc
borate or a mixture of the borate and hydroxide. 4. Tannic
acid gives a precipitate with concentrated solutions of zinc salts,.
5. Zinc salts coagulate albumin.
PRESCRIPTIONS WITH CRITICISMS.
In studying the following prescriptions the student
should try to make out for himself, so far as possible,
wherein the trouble lies, and what he would do to prevent or
remedy it, before referring to the notes. In order not to
overlook any of the incompatibilities it is suggested that he
find out what effect, if any, the first ingredient may have on
each of the others ; then the second ingredient, the third, and
so on. Then, taking the prescription as a whole, he should
determine the color that will be produced, the nature and
color of the precipitate, how one incompatibility will be
modified by another, etc. The student should practice trans-
lating the Latin into English, and the English into Latin.
The majority of prescriptions which follow should be filled,
unless in the reaction there is some more active or dangerous
compound formed. It must not be forgotten that a variation
in the proportions of ingredients modifies the results of com-
Hydrargjrri chloridi cor., gr. ij
Potassii lodidi, 3 ij
Syrupi rhei aromatici, f. | iv
Elixiris cinchonae, f. | iv
Misce et signa : Teaspoonful
three times a day.
Quininas sulpbatis, gr. xx
Acidi sulphurici aromat., f. 3 ss
Ammonii carbonatis, 3 j
Syrupi aurantii, q. s. ad f . § iv
M. S. Cochleare parvum
t i. d.
Calomel, gr, vj
Potassium chlorate, 3j
Sugar, powd., 3 j
Mix and make six powders.
Label : One every two hours.
Syrupi scillae, aa. f . | i j
Misce et fiat solutio.
Sig. Teaspoonful when cough-
INCOMPATIBILITIES IN PRESCRIPTIONS.
Quininae sulphatis, 3ij
Oiei carophylli, gtt ij
Potassii permanganatisy gr. iij
Acidi sulphur, aromat, f. 3 ij
Mucilag. acacise, q. s.adf. | viij
M. S. Tablespoonful every
Muc. acaciae, aa. f. § j
M. S. Teaspoonful every
Bismuthi subnitratis, 3 ij
Sodii hypophosphitis, 3 j
Extracti nucis vomicae, gr. v
Misce, flat pulvis et divide in
partes aequales No. xxv.
Hydrargyri chloridi cor., gr, i
Ammonii iodidi, aa. 3 i j
Potassii chloratisy 3 j
Aquae, f . | j
Syrupi sarsaparillae co., f* | iv
M. S. Teaspoonful in wine-
glass of water after each meal.
Potassium chlorate, gr. xl
Sodium hypophosphite, gr. xxx
Water, enough to make f. | xx
Mix and label : Use as gar-
Zinc sulphate, aa. 3 ss
Mix. Dissolve one teaspoon-
ful in cup of water.
Fluideztracti buchu, f. f ss
Spiritus aetheris nitrosi, f. § j
Potassii acetatis, 3 ij
Syrupi, q. s. ad f. | iv
Misce et signa: Teaspoonful
half hour after meals.
Tinct. digitalis, f. 3 ij
Tinct. ferri chloridi, f. 3 iss
Acidi phosphorici diluti, f. 3 j
Aquae, q. s. ad f. § ij
M. S. Teaspoonful in some
water twice a day.
Syrupi aurantii cort.,
ad f . I iv
M. S. Teaspoonful every four
Sugar of lead,
Mix and label : Lotion.
Acidi sulphurici arom
Syr. eriodictyi arom..
ad f. Iij
M. S. Teaspoonful
INCOMPATIBILITIES IN PRESCRIPTIONS.
Syr. ferri iodidi,
M. S. Dessertspoonful
Liq. arseni et hydrarg. iodidi,
Potassii iodidi, 5 Gra.
Quininae sulphatis, 2 Gm.
Acidi sulphurici aromat., q. s.
Synipi, q. s. ad 300 Cc.
M. S. 4 Cc. after each meal.
Sodii salicylatis, gr. xx
Quininse sulphatis, gr. xx
Synipi zingiberis, f. | ij
M. S. Teaspoonful doses.
Liquoris acidi arsenosi,
Hydrargyri chlor. cor.,
Spiritus vini rectificati,
Aquae, *. ^ j
Misce. Signa : Teaspoonful
night and morning.
Potassii bromidi, 3 iij
Chloralis, 3 iv
Elixiris aromatici, q. s. ad f. ^ ij
M. S. Take offe teaspoonful
Plumbi subacetatis, 3 ss
Zinci sulphatis, gr. xl
Tinct. catechu co.,
Tincturae opii, aa. f . 5 ss
Aquae, q. s. ad f. I viij
M. S. Injection. Shake well
Hydrargyri chloridi cor., gr. iij
Albuminis, 3 iss
Aquae, q. s. ad f . ^ x
Misce et cola.
Signa: Teaspoonful three times
Sodii phosphatis, 3 v
Synipi rhei, f. 3 iv
Synipi, f. I 88
Aquae, q. 8. ad S ij
M. S. Teaspoonful in a little
water before meals.
Ammonii carbonatis, gr. xx
Ammonii chloridi, gr. xxx
Syrupi allii, f . 5 J
Aquae, q. s. «d f. S ij
M. S. One-half teaapoonful
M. S. Put one drop in each
eye night and morning.
q. s. ad f . 3 j
INCOMPATIBILITIES IX PRESCRIPTIONS.
Syrupi ipecac, aa. f. 3 j
Syrupi eriodict3ri arom., f. 3 ij
Potassii iodidi, 3j
Spiritus setheris nit, f. 3 ij
Glycerini, f. 3 iv
Syrupi acidi citrici,
q. s. ad f. § iij
Misce. Signa : Teaspoonful
Tinct. ferri chlor., f. | j
Tinct. iodi comp.,
Liq. pot. arsenit.,
Ac. phosphor, dil., aa. f. 3 iv
Quininae sulph., 3 j
Rhei pulv., § ss
Aquae, q. s. ad f. | viij
Sig. Teaspoonful after
Quinine sulphate, 3 j
Strychnine sulphate, gr. j
Sulphuric acid dil., 3 ij
Iron pyrophosphate, sol., 3 j
enough to make f. | vj
Mix. Teaspoonful three times
Iodine, gr. xxx
Spirit of camphor, f. | j.
Soap liniment, f. 5 iij
Mix and label : Apply as di-
Pepsini saccharati, 3 ij
Bismuthi et ammon. cit, 3 j
Acidi hydrochlorici dil., gtt xl
Aquae, f. | ij
Misce et fiat solutio.
Sig. Dose, one teaspoonfuL
Sodii hypophosphitis, gr. xx
Acidi sulphurosi, 3 j
Aquae cinnamomi, q. s. ad f. § ij
M. S. Teaspoonful for vom-
Hydrargyri chlor. mit, gr. vj
Potassii iodidi, gr. xl
Misce et fiat pulvis et in t:har-
tulas decem divide.
Signa: One powder after each
Tinct. nucis vom.,
Elixiris cinchonae co..
aa. f . 3 ij
f . I iiiss
M. S. Teaspoonful in an
ounce of water after meals.
Tinct. cardam. co.,
Aquae fontanae, q. s. ad O. ss
M. S. Take one tablespoon-
ful night and morning.
aa. f. % ij
INCOMPATIBIUTIES IN PRESCRIPTIONS.
Ammonii carbonatis, 3 j
Syrupi ipecacuanhae, f. 3 j
Misturse amygdalse, aa. f. ^ j
M. S. Teaspoonful in milk