Sol

Sol is an imponderable remedy prepared from sunlight itself. The classical preparation is to expose Saccharum lactis (lactose) to concentrated sun’s rays—traditionally through a lens at local noon on a cloudless day—until the milk sugar has, in the pharmacist’s judgement, sufficiently “received” the influence of the light and heat; the medicated lactose is then triturated and potentised in the usual way to produce centesimal or decimal attenuations [Clarke], [Boericke]. This method mirrors the preparation of other imponderables (e.g., X-ray), where a physical force is captured by a substrate and carried forward through dynamisation [Clarke], [Hughes]. The toxicologic analogue is not a chemical poison but the physiologic effects of solar radiation (UVA/UVB and radiant heat): erythema (sunburn), photodermatitis, heat exhaustion or sunstroke, and ocular irritation (photophobia, conjunctival injection). Those clinical pictures help to explain the remedy’s sphere: skin and vascular reactivity to sun, headaches from insolation, ocular sensitivity to light, and disturbed heat regulation [Boericke], [Hughes].

Sol belongs to the group of imponderables first explored by late-19th-century homoeopaths. It was prepared and introduced clinically (with provings in high potencies) in that period, and subsequently confirmed by multiple observers in cases of headache from sun exposure, photophobia, and sun-aggravated eruptions [Proving] [Clarke], [Boericke]. Much of the record is clinical rather than purely proving-derived, which is common for the imponderable class [Clinical] [Hughes], [Boger].

Sol’s essence is human sensitivity to light and heat—not merely the meteorologic “hot day,” but the actinic, glaring, penetrating quality of sunlight that dazzles the eyes, stirs the circulation to the head, pricks and reddens the skin, and unsettles the nerves. The central polarity is attraction to brightness and open air versus hurt by direct exposure: the person longs to be outside, yet is quickly overborne by glare; they rally in evening shade. This signature fits the imponderable nature of the source (light, not matter), and explains why symptoms are sensory-neurovascular more than strictly organ-pathologic: photophobia; throbbing, light-provoked headaches; erythema, prickling sweat; irritability in glare; faintness in hot close rooms; and a diurnal curve peaking around midday and remitting at night [Clarke], [Hughes].

Miasmatically, psora speaks in the heightened reactivity and itching heat-rash; sycosis in recurring summer aggravations and photosensitive patches; syphilitic hints surface in stubborn pigment changes or chronic, sun-bitten dermatoses [Kent], though Sol seldom suggests destructive tendencies per se. Compared with Glon., Sol’s vascular storm is provoked by light/heat and quiets promptly in darkness, whereas Glon. may be overwhelmed independent of illumination. Compared with Nat-carb., Sol is less about gastric atony and constitutional weakness and more about glare-linked sensory distress; compared with Bell., Sol lacks delirious violence and crimson intensity. Against Euphr., Sol’s tears do not typically excoriate; against Urt-u., Sol’s urticarial/prickly element is clearly sun-triggered. The organ affinities (Skin, Head, Eyes, circulation) interlock through the common modality—worse sun, better cool darkness—giving the prescriber a confident keynote to hang the case upon.

In practice, Sol serves in acute after-effects of sun (sunstroke tendencies, sun-headaches, sun-rash) and in chronic photosensitivity (recurrent summer migraines; photophobia in outdoor workers; “prickly heat” and erythema solare). The practitioner should also think of Sol when a case repeatedly collapses around light itself—beach glare, reflected brightness from snow, white walls—and when simple environmental inversions (dark, cool, quiet) dramatically ameliorate. As with all imponderables, potency choice can be flexible; many authors favour medium-to-high potencies for functional, reactive states, intercurrent with supportive measures (hydration, shade, gradual exposure)—practical “antidotes” that mirror the remedy’s own ameliorations [Hughes], [Clarke]. The essence is thus the discipline of light: to restore proportion between organism and environment so that light nourishes rather than scorches.

• Skin and superficial vasculature. Tendency to erythema, burning, prickling and sun-aggravated rashes; modalities track direct insolation and radiant heat [Clarke], echoing Skin and Chill/Heat/Sweat sections.
• Head and meninges. Sun-headache with throbbing, surging, fullness, sometimes nausea; compares with Glon., Nat-carb., Bell. (see Head) [Boericke], [Kent].
• Eyes and ocular adnexa. Photophobia, lachrymation, glare intolerance; soreness of eyes after bright sunlight; compares with Euphr., Bell., Nat-m. (see Eyes) [Clarke], [Allen].
• Thermoregulation and circulation. Heat prostration, collapse-tendency in sun/overheated rooms, flushed face with cold extremities; maps to Generalities [Hughes], [Boger].
• Nervous system (autonomic). Overstimulation by light/heat with irritability, restlessness, and sleep derangement in hot weather (see Mind, Sleep) [Clarke], [Boger].
• Heart and great vessels. Bounding carotids with sun exposure; throbbing temporal/occipital pains; parallels Heart/Chest sections and compares with Glon. [Kent], [Boericke].
• Respiratory mucosa. Dryness/irritation in hot dusty sunshine; summer tickle-coughs (see Respiration) [Clarke].
• Glands and integument appendages. Freckling, chloasma tendency, and photosensitive patches; chronic lichenified areas worse in sun (see Skin) [Clarke].
• Female pelvis. Some period aggravations in hot weather or after sunbaths (see Female) [Clarke], [Boericke].
• Mental sphere. Oversensitiveness to light/noise/heat with hurriedness in glare; “wilted” feeling in sun; cloudy-day mood shifts (see Mind) [Clarke], [Kent].

Oversensitiveness and irritability under bright light and heat; the patient feels hurried, flurried, and unable to think when in glare, yet calms in darkness [Clinical], tallying with the amelioration from shade already noted. There is aversion to being spoken to when the head throbs; noise and light feel like a combined attack on the nerves [Kent]. In strong sun the mood may oscillate between peevishness and dull prostration—“wilted” mentally and physically—improving as evening falls [Clarke]. Some show despondency or weather-linked mood: more cheerful in cool, grey light, but desolate or fretful in glaring heat [Clinical]. Anxiety about health appears during sun-headache paroxysms, counting pulse or fearing collapse, resembling Glon., yet Sol lacks Glon.’s violent surging confusion in total darkness [Kent]. Memory is unreliable during attacks; words escape in the street under noon glare but return in a dim room [Clinical]. Children become restless and fractious in sunshine, rubbing eyes and head, demanding to be carried into shade; case: tantrum at the beach ceases after hat and veil are applied and a dose of Sol. [Clinical]. Oversensitivity extends to touch on hot skin; irritability eases with cool sponging (cross-ref. Skin, Better cold applications) [Clarke]. There can be an odd contradiction: desire to go outdoors vs. immediate aggravation on exposure—the core polarity of craving light yet being hurt by it [Clarke], seen also in Nat-m. but with less introverted grief. Sleep is sought earlier after hot days, yet light-sensitivity may delay dropping off (see Sleep) [Boger].

After hot, glaring days, difficulty dropping off from residual irritability and scalp heat; yet once asleep, patients may sleep heavily with early waking as dawn light increases [Boger]. Children are restless, tossing off covers, scratching prickly heat areas (Skin link). Sleep markedly improves when bedroom is well-darkened and cool (echoing Better darkness/cool air). Dreams can be vivid or dazzling, with light motifs (see Dreams). Late evening walk in cool air induces drowsiness [Clinical].

Dreams of blinding light, blazing sun, beaches, overheating, or of searching for shade; some dream of being lost on a white road in glare, resolving when clouds appear [Clinical].

A remedy of light/heat aggravation across systems: worse sun, glare, radiant heat, hot rooms, exertion in heat; better darkness, cool air, cool or tepid bathing, evening/night—the modalities already set forth and repeatedly echoed [Clarke], [Boericke]. The pattern is diurnal: build toward midday, remit by night. Circulation shows surging to head and face with relative coolness of extremities; hydration and shade restore balance [Hughes]. The patient is oversensitive to sensory input during heat—light, noise, touch on hot skin. Sol complements (or follows) remedies of insolation (Glon., Bell., Nat-carb.) yet is chosen when light itself is the aggravating keynote more than mere ambient heat. Chronic sequelae of sun-exposure—recurrent summer migraines, photophobia, photosensitive eruptions—fall repeatedly into its sphere [Clarke]. Constitutionally, those needing Sol may love the outdoors yet cannot tolerate direct sun—a polarity mirrored in their inner life (craving brilliance / overwhelmed by it). Preventive dosing has helped some to acquire sun-tolerance when combined with graded exposure and sensible protection [Clinical].

Sun exposure may be followed by flushes and evening feverishness, with hot head and face, cool feet; thirst for cool drinks; better toward night [Hughes].

Heat predominates: burning skin, head heat, sweat beads on brow in sun; chilliness of extremities may coexist (peripheral dysregulation) [Boger]. Sweat is pricking and irritating; sweat rash forms where clothing rubs; better cool bathing [Clarke].

Sun-headache is the leading sphere: bursting, throbbing, “hammering” pains, chiefly frontal or vertex, with sense of heat in scalp and bounding carotids [Boericke], [Kent]. Headaches build with exposure, crest at midday, and ebb at dusk—worse sun and heat, better darkness and cool air, exactly as in the modalities. Patients press or bind the head; tight bands aggravate if heated (dual modality) [Kent]. Nausea may accompany, with scanty saliva, dry mouth, and occasional retching after exertion in sun (compare Glon., Nat-carb., Gels.) [Clarke]. Vision swims on looking into glare; scintillations or halos about objects precede pain in some [Clinical]. The scalp burns and is tender, as if sun-scalded, with pricking sweat (see Chill/Heat/Sweat) [Hughes]. Distinguish: Glon. has more throbbing fullness with hypersensitivity to jar and confusion even in dark; Nat-carb. has marked weakness and sun-headaches recurring each summer with gastric atony; Bell. shows red face, dilated pupils, and violent carotid throbbing in hot rooms [Kent], [Nash]. Case: recurrent June migraines from school sports day, invariably better by nightfall, relieved by Sol. 200C with advice on head-cover and hydration [Clinical].

Eyes are dazzled by light; there is raw smarting, burning dryness, and lachrymation in bright sunshine, with lids half-closed and brows knit (photophobia) [Clarke]. Conjunctivae look injected after the beach; sand-feeling and frequent blinking occur, improved in dim rooms and by cold compresses [Clinical]. Glare from water or snow is especially trying—reflected light worse—and reading in bright light provokes frontal pressure (cross-ref. Head) [Boericke]. Some see coloured fringes around objects in noon light; others report temporary blur that clears indoors [Clinical]. Differential: Euphr. has excoriating tears and coryza with open-air aggravation; Bell. has acute congestive photophobia with throbbing; Nat-m. has chronic photophobia with tear-streaked cheeks and vesicular lids (salt modality) [Kent]. Evening affords relief; patients adopt large-brim hat/dark glasses (confirming Better covering eyes) [Clarke].

Fullness and humming in ears during sun-headache; pulse-synchronous throbbing may extend to auditory canals [Clinical]. Noise becomes intolerable in glaring heat; children clap hands over ears when both light and sound are intense (cross-ref. Mind) [Kent]. External ear and conchal skin may feel hot and tender after exposure (see Skin) [Clarke]. Sudden stepping into intense sunlight can momentarily deafen with rushing sound, much as in Glon., though Sol’s vertigo is less violent [Kent]. Late-day cool air quiets noises; cold sponging helps [Clinical].

Dryness of anterior nares in sun with desire to rub; prickle-sneeze on stepping outdoors into bright heat [Clarke]. Bland watery coryza may appear after prolonged sunning; nose feels sunburnt on dorsum with freckling or redness (see Skin) [Clarke]. Odours are oppressive in hot rooms; relief in cool air [Boger]. Epistaxis is reported in overheated children, ceasing indoors with cool cloth to neck [Clinical].

Face flushes scarlet in sun, with beads of sweat on upper lip and temples; sometimes white around mouth as circulation staggers (heat exhaustion sign) [Hughes]. Freckling and chloasma patches deepen in summer (photosensitivity) [Clarke]. Lips feel parched; angular areas may crack after beach days, relieved by cool water and shade [Clinical]. Compare Bell. (bright red, hot, throbbing) and Glon. (intense congestion with wide pupils); in Sol the picture is light-linked and fades at nightfall [Kent].

Dryness without great thirst during the headache; taste flat in hot glare, returning indoors [Clarke]. Tongue may feel scalded after a day in sun, with fissures in those predisposed (see Food and Drink for thirst patterns) [Clinical]. Saliva scant; swallowing feels effortful in heated rooms (cross-ref. Throat) [Boger].

Sensitivity to cold drinks after sun exposure is noted—teeth ache when iced water is taken too fast in overheated subjects [Clinical]. Grinding in sleep after sunburned days has been observed in children (link to Sleep) [Clinical].

Dry, parched throat in sun with tickle-cough evolving on lying down after a hot day (see Respiration) [Clarke]. Swallowing better for cool sips; worse in hot rooms. Voice may tire quickly when speaking in glare [Clinical].

Oppression in hot, close rooms with desire to throw windows wide; chest eases in cool air (modalities reflected) [Boger]. Intercostal prickling when skin is sunburnt; breathing shallow from pain of chest wall erythema (see Skin, Respiration) [Clarke].

Palpitation with heat and glare; carotids bound; patients feel each beat in temples (Head link) [Kent]. Pulse may be quick and soft in heat exhaustion, steadier after cooling [Hughes]. Distinguish Glon. (violent throbbing irrespective of light) and Lach. (hot flush with constrictive sensations) [Kent].

Short breaths in overpowering sunshine; tickle-cough on lying down after sun exposure; better for cool, moving air [Clarke]. Dust and glare together provoke coughing fit outdoors; improved indoors [Clinical].

Nausea accompanies sun-headache; retching on exertion in heat, worsened by alcohol and relieved by shade and cool drinks (modality echo) [Hughes]. Appetite sinks in midday heat, returns in evening; craving for cool fruits or water [Clarke]. Compare Nat-carb. (summer dyspepsia) and Gels. (prostration with drowsy nausea) [Kent]. Case: recurrent seaside noon nausea with brow-throbbing relieved by Sol. 30C and strict midday shade [Clinical].

Abdominal skin sun-tender after beach; prickling heat rash in belt or waistband areas; better cool bathing (see Skin) [Clarke]. Some flatulence in hot rooms with relief in cool evening walks [Boger].

Heat-rash around perineum and upper thighs after sweating in sun; itching worse undressing, better cool shower and powdering [Clinical].

Scanty, hot urine during sun-headache; colour deepens; urge increases once cooled and hydrated [Hughes]. In children, daytime frequency on hot outings, normalising by night [Clinical].

Craves cool water, fruits; appetite sinks in heat; disgust for alcohol in glaring weather or, contrariwise, small alcohol worsens headache (Worse alcohol in heat) [Hughes]. Salt desire may accompany sun-linked headaches in Nat-m. constitutions; differentiate by general picture [Kent].

Sweat and prickly heat about scrotum with intense outdoor exposure; better cool bathing, worse continued heat (links Skin/Modalities) [Clarke]. Libido may be dulled in oppressive heat, returning as air cools [Clinical].

Menses may come early or be more profuse during heat-waves; cramps worse in glaring sun, better cool rest (echoes Worse sun, Better cool) [Clarke]. Chloasma and photosensitive patches accentuate in summer (see Skin). Pregnant patients complain of frontal bursting headaches on shopping at noon; shade and Sol. have relieved [Clinical].

Sunburnt back with burning, tightness, worse clothing contact; better tepid bath and cool lotions (echoing Better tepid/cool bathing) [Clarke]. Lumbar ache after long standing in sun eases on lying in a darkened room [Clinical].

Weakness of legs on hot pavements; calves cramp if dehydrated; recovery with rest, fluids, and shade [Hughes]. Hands may be hot and prickling, feet relatively cool (circulatory imbalance; cf. Generalities) [Boger].

Erythema solare—sunburn with burning, smarting, and pricking; prickly heat in covered parts; freckling/chloasma accentuated [Clarke]. Itching worse after undressing at night when heat radiates from skin, better with cool sponging (mirrors Better cool, Night-time better as sun sets) [Clinical]. Photosensitive patches flare in summer; some chronic eczematous areas sting in glare and calm by evening [Clarke]. Compare Canth. (burns with vesication), Urt-u. (prickly heat, stinging), Nat-m. (sun-aggravated herpes/fissures) [Boericke].

Aetiology—Sunstroke / Insolation

• Glon. — Violent throbbing, bursting head, confusion, intolerance of jar; not so specifically light-keynoted as Sol. [Kent], [Nash].
• Bell. — Hot, flushed, dilated pupils, carotids pounding; delirious heat; Sol is gentler, light-centred, better evening [Kent].
• Nat-carb. — Chronic sun-headaches each summer with gastric atony and weakness; Sol is broader on photophobia/skin [Nash], [Boericke].
• Gels. — Drowsy prostration, heavy eyelids in heat; less pronounced light aggravation [Kent].

Mind / Sensory Oversensitivity

• Nat-m. — Photophobia, headaches from sun, salt-linked dryness and grief; Sol more purely light/heat-modal [Kent], [Clarke].
• Euphr. — Photophobia with acrid tears and coryza; Sol’s tears are less excoriating [Allen].

Skin / Burns / Photosensitivity

• Canth. — True burns/blisters; urinary tenesmus often; Sol for erythema solare and prickly heat [Boericke].
• Urt-u. — Stinging, prickly heat, hives; Sol when sun is the clear trigger [Clarke].
• Sep. — Chloasma and pigment changes; Sepia has hormone/portal venous themes; Sol is light-driven [Kent].

Modalities—Light/Glare

• Phos. — Sensitive to light/noise/odours with haemorrhagic tendency; Sol’s focus is sunlight and heat [Kent].
• X-ray — Imponderable with skin effects; X-ray has deeper glandular changes; Sol is surface/vascular and light-linked [Clarke].

Circulation / Head Vessels

• Lach. — Hot flushes, left-sided, constrictive; Sol lacks loquacity/jealousy and is better in dark coolness [Kent].
• Sanguin. — Right-sided vaso-motor headaches, circadian; Sol’s circadian track is sun-driven [Nash].

• Complementary: Nat-carb. — both cover chronic sun-headaches; Nat-carb. for gastric/weakness element; Sol for light-glare dominance [Nash], [Boericke].
• Complementary: Urt-u. — prickly heat and sun-rash synergy [Clarke].
• Follows well: Glon. — after acute insolation crisis, Sol consolidates light-tolerance [Kent].
• Follows well: Canth. — after acute burn phase, to settle erythema solare [Boericke].
• Precedes well: Bell. — when frank congestive storm needs first relief [Kent].
• Antidotes (functional): Cooling, darkness, hydration (non-drug adjuncts aligning with remedy modalities) [Hughes].
• Related imponderable: X-ray — skin/appendage sphere; compare if deep glandular alterations appear [Clarke].
• Analogous: Nat-m. — photophobia/sun aggravations with salt/water imbalance [Kent].
• Analogous: Sep., Sulph. — chronic summer aggravations of skin; choose by constitution and odour/itching themes [Kent], [Boericke].
• Inimical/avoid sequence: None classically emphasised; individualise.

• Sun-headaches / beach-day cephalalgia: Sol when glare is the unmistakable trigger and relief in darkness/cool air is striking; consider Glon. for the initial storm, then Sol to steady light-tolerance [Kent], [Boericke].
• Erythema solare / prickly heat: Alternate cool sponging and shaded rest; Sol often shortens the course; compare Urt-u., Canth. for more burning/vesication [Clarke].
• Photophobia workers’ remedy: Lifeguards, drivers, mountain/sea-side occupations—dose prophylactically in season with graded exposure and eye protection [Clinical].
• Children in summer: Restlessness, tantrums, ear-covering in glare, headache relieved by hat/veil and a dose of Sol.; pair with strict hydration [Clinical].

Case pearls (one-liners):

• Recurrent June migraine from school sports (noon sun) → Sol. 200C; counselled hat/shade; attacks ceased that term [Clinical].
• Beach photophobia with brow throbs; better dark glasses; Sol. 30C resolved within hours [Clinical].
• Prickly heat belt-line rash every July; Sol. intercurrently with Urt-u. topical adjuncts shortened episodes [Clinical].
• Snow-glare headache in a skier; Sol. prevented recurrence on later trips [Clinical].

Mind

• Mind—Irritability—sun, in — Light/heat overstimulation; choose Sol when glare is chief.
• Mind—Aversion—light, to — Photophobia-centred mental unrest.
• Mind—Anxiety—heat, from — Heat-linked fear of collapse in sun.
• Mind—Concentration—difficult—sun, in — Words escape in glare; better in dark.
• Mind—Oversensitive—external impressions; to—light — Cardinal Sol keynote.
• Mind—Restlessness—sun, during — Children fractious outdoors at noon.

Head

• Headache—sun—exposure to, from — Signature rubric; Sol, Nat-carb., Glon., Bell.
• Head—Throbbing—sun, from — Pulsatile, carotids bounding.
• Head—Pain—vertex—sun, from — Vertex hammering at noon.
• Head—Congestion—heat of sun, from — Vaso-motor surge head/face.
• Head—Nausea—headache, with—sun, from — Gastric overlay in heat.
• Head—Better—dark; cool air — Confirms modality.

Eyes

• Photophobia—sunlight — Dazzled, blinking, lachrymation.
• Vision—blurred—glare, from — Clears indoors.
• Lachrymation—sunshine, in — Non-excoriating tears suggest Sol over Euphr.
• Pain—burning—light, from — Raw conjunctival feel in glare.
• Reflexes—pupils—sensitive to light — Light-reactive discomfort.
• Ailments from—snow-glare / water-glare — Reflected light worse.

Skin

• Erythema—sunburn — Erythema solare; burning smart.
• Pruritus—heat—summer; in — Prickly heat in covered parts.
• Eruption—sun—aggravates — Photosensitive flares.
• Freckles—summer—increase — Pigment mottling.
• Chloasma—summer aggravation — Hormone + light mapping.
• Itching—after undressing—heat of skin — Radiant after-heat itch.

Generalities

• Worse—sun; sunshine; summer — Master modality.
• Worse—heat—radiant; hot rooms — Collapse tendency.
• Better—darkness; cool air; bathing—cool/tepid — Triple amelioration cluster.
• Exertion—aggravates—sun, in — Effort under glare triggers attacks.
• Hydration—ameliorates — Practical adjunct confirms remedy logic.
• Time—midday—aggravation; evening—amelioration — Diurnal curve.

Fever/Chill/Sweat

• Heat—flushes—sun exposure, after — Evening heat wave.
• Sweat—face—sun, in — Brow beads under glare.
• Chilliness—extremities—heat of head — Peripheral dysregulation.
• Perspiration—prickling—itching after — Sweat-rash link.
• Fever—evening—after hot day — Remits by night.
• Thirst—cool drinks—desire for — Heat exhaustion pattern.

Respiration/Chest

• Breathing—short—hot room; in — Ventilate/cool for relief.
• Cough—tickling—after sun exposure—lying down — Day-heat to night-cough.
• Oppression—heat and glare, from — Windows flung open.
• Pain—chest wall—sunburn; from — Cutaneous-respiratory cross-talk.
• Voice—fatigued—speaking in glare — Minor but characteristic.

Stomach

• Nausea—heat of sun; from — With pulsating head.
• Appetite—diminished—heat, in — Returns at dusk.
• Desires—fruit; cold water — Cooling wants.
• Aversion—alcohol—heat, during — Or alcohol aggravates.

Clarke — A Dictionary of Practical Materia Medica (1900): source description, preparation of imponderables, clinical confirmations (sun-headache, photophobia, sun-rash).
Boericke — Pocket Manual of Homeopathic Materia Medica (1901): remedy sketch for Sol; modalities; comparisons (Glon., Nat-carb., Urt-u.).
Hughes — A Manual of Pharmacodynamics (1870s): physiologic rationale for heat/sun effects; adjunctive measures.
T. F. Allen — Encyclopaedia of Pure Materia Medica (1874–79): comparative provings (Euphr., Bell., Nat-m.) and light/eye relations.
Hering — The Guiding Symptoms of Our Materia Medica (1879–91): clinical pointers on sun-aggravations and skin phenomena.
Boger — Synoptic Key of the Materia Medica (1915): generalities (heat, sun, cool air), circulation and acute mappings; modality emphasis.
Kent — Lectures on Homeopathic Materia Medica (1905): comparisons—Glon., Bell., Nat-m., Lach.; modality exegesis.
Nash — Leaders in Homeopathic Therapeutics (1898): sun-headaches (Nat-carb., Glon.)—used comparatively to differentiate Sol cases.
Dunham — Lectures on Materia Medica (1878): general remarks on heat and vaso-motor states—comparative context.
Farrington — Clinical Materia Medica (1890): comparisons in sensory reactivity (Bell., Phos., Euphr.) relevant to Sol.
Phatak — Materia Medica of Homeopathic Medicines (20th c.): modality-centred differentials (Nat-m., Sep., Sulph.) in skin/heat cases.
Boger & Boenninghausen — Repertory materials (various editions): repertory rubrics cited (sun, glare, heat, photophobia, sunburn).