Chemistry
Chemistry studies the composition, properties and transformations of matter. In Dr Stone, it is at the heart of nearly every Senku invention, from soap (saponification) to nitric acid extracted from bat guano, including iron metallurgy and sulfa drugs.
Entries in this discipline
Activated Charcoal
In The Apothecary Diaries, Maomao gives activated charcoal in an emergency. Why does it work? How does adsorption trap toxins? Its real limits.
Anthocyanins
In The Apothecary Diaries, Maomao reveals why blue roses are impossible. We explain anthocyanins, their response to pH, and their antioxidant property.
Antiseptic Alcohol
In The Apothecary Diaries, a distilled alcohol is called a highly effective disinfectant. We explain why ethanol kills germs, and at what concentration.
Beeswax
Beeswax, a hydrophobic mix of esters that melts around 62°C. Candles, ointments, waterproofing, lost-wax casting: its ancient uses explained.
Black Powder
In The Apothecary Diaries, Maomao states the exact formula for black powder. We explain the role of each ingredient, the reaction, and the rotten-egg smell.
Carbon Monoxide
In The Apothecary Diaries, embers bring guests down at a party. We explain carbon monoxide, why it suffocates without warning, and the right thing to do.
Clay and Kaolin
In The Apothecary Diaries, clay is used as makeup. We explain kaolinite, its layered structure, its absorbent power, and its uses.
Dust Explosion
Yes, when it hangs in the air at the right concentration. The three conditions, explosibility limits, silo disasters, and the warehouse in The Apothecary Diaries.
Elixirs of Immortality
Cinnabar, mercury, arsenic: Chinese waidan alchemy sought eternal life in poisons. The alchemists' logic, what mercury does to the brain, and who died of it.
Revealing Fingerprints
Revealing fingerprints with flour. We explain the chemistry of latent prints and the history of dactyloscopy, born in ancient China.
Flame Coloration
Each metal emits its own color: yellow for sodium, blue-green for copper, red for strontium. The quantum mechanism, fireworks, and the clue in The Apothecary Diaries.
Galenic Formulations
In The Apothecary Diaries, an ointment gets prepared. We explain galenics: how a medicine's form determines how an active ingredient is absorbed.
The Glass Mirror
Why does a glass mirror give a far sharper image than polished bronze? The history of Venetian silvering and the chemistry of mirror-making.
Gluten
In The Apothecary Diaries, wheat-flour glue illustrates gluten. We explain glutenins, gliadins, viscoelasticity, and celiac disease.
Honey Preservation
Honey has preserved food for millennia. Here's why: low water activity, osmolarity, acidity, and hydrogen peroxide all work together to stop microbes.
Hot Springs and Sulfur
In The Apothecary Diaries, hot springs provide sulfur for gunpowder. We explain the geothermal gradient, the smell, and native sulfur deposits.
Insect Pheromones
In The Apothecary Diaries, crushed insects draw swarms of males. We explain pheromones, the silkworm moth's bombykol, and their modern uses.
Invisible Ink
In The Apothecary Diaries, Maomao hides a message in alcohol revealed by flame. We explain why fruit juice, milk, or alcohol brown before the paper does.
Lead White Makeup
Ceruse is lead carbonate: worn daily, it caused slow lead poisoning. The symptoms, why it killed nursing infants, and the palace curse in The Apothecary Diaries.
Mercury
In The Apothecary Diaries, quicksilver goes into a court poison. We explain mercury, its toxicity, and the immortality elixirs that killed emperors.
Musk
In The Apothecary Diaries, Maomao recognizes the scent of musk. We explain muscone, the musk deer's gland, and synthetic musks.
Oxalic Acid
Sharper than lemon's citric acid. Why oxalis, sorrel and rhubarb stay edible, and when oxalates start forming kidney stones.
Papermaking
In The Apothecary Diaries, Maomao diagnoses crumbly paper. We explain papermaking, cellulose, and Cai Lun's invention.
Perfume Extraction
In The Apothecary Diaries, Maomao distills roses. We explain steam distillation, enfleurage, terpenes, and why natural perfume costs so much.
Orpiment and Arsenic
In The Apothecary Diaries, a yellow pigment poisons slowly. We explain orpiment, arsenic, and the chronic poisoning of court painters.
Plant Ashes
In The Apothecary Diaries, ash is scattered to repel insects. We explain potash, alkalinity, and the ancient uses of wood ash.
Salt, Ice, and Cold
Maomao makes ice cream with no refrigerator. We explain freezing-point depression, the NaCl-water eutectic point at -21°C, and colligative properties.
Salting and Brining
In The Apothecary Diaries, Maomao dates a batch of seaweed using her knowledge of brining. We explain how salt preserves food, and why it eventually fails.
Silver and Poison Detection
Not to poison itself: silver tarnishes from sulfur, not arsenic. Why the old silver spoon test seemed to work, what it misses, and what The Apothecary Diaries gets right.
Soap
In The Apothecary Diaries, dispensary soap stings the eyes. We explain saponification, amphiphilic molecules, and micelles.
Sugar and Confectionery
Sucrose, crystallization, the states of cooked sugar, and sugar preservation: the chemistry behind the confections mentioned in The Apothecary Diaries.
Acetanilide
An 1886 painkiller and fever reducer that works by turning into paracetamol in the liver, but harms the blood. Why it was dropped, and Senku's choice in Dr Stone.
Aconite
Senku panics at the sight of aconite: we explain why this plant is deadly, its mechanism on sodium channels, and its ethnobotanical history.
Activated Carbon
In Dr Stone, Senku activates charcoal for his gas mask. We explain activation, porosity, and the adsorption that traps molecules.
Brandy
Senku turns his wine into brandy by distillation: we explain medieval eau-de-vie, alchemical aqua vitae, and how you get to 40-proof spirit.
Black Powder
Roughly 75% saltpeter, 15% charcoal, 10% sulfur. What each ingredient does, why it deflagrates instead of detonating, and the sulfur mistake in Dr Stone.
Caffeine
Senku brews a caffeine stimulant from tea leaves. We explain how caffeine acts on the brain, its real effects, and how much of the power-up drink is myth.
Calcium Carbonate
Senku presents calcium carbonate as civilization's cornerstone: we explain CaCO₃, the lime cycle, and its uses in agriculture and construction.
Camphor Tree
The camphor tree that shelters Yuzuriha for 3,700 years: we explain the chemistry of camphor, terpenes, and this Japanese tree's age-old uses.
Destroying Angel
Senku recognizes the destroying angel on sight: we explain why this mushroom is deadly, the molecular mechanism of α-amanitin, and the treatments available.
Distillation
Senku distills his wine in Dr Stone: we explain the physical principle, Raoult's law, the 95.6% water-ethanol azeotrope, and 5,000 years of history.
Dynamite
Alfred Nobel, in 1867: soaked into diatomaceous earth, nitroglycerin became safe to carry. Why that works, what it changed, and the dynamite in Dr Stone.
Food Preservation
Senku preserves food with salt: we explain water activity, bacterial osmosis, and the four great primitive preservation methods.
Guano and Nitrification
Senku exploits bat droppings to produce nitric acid: we explain bacterial nitrification and the history of saltpeter.
Food Smoking
Tsukasa smokes his meat in Dr Stone: we explain the chemistry of smoke, the role of aldehydes and phenols, and the modern health risks.
Lime Mortar
Senku proposes building with mortar: we explain the chemistry of hydraulic set, the secret of Roman concrete, and the shift to modern lime.
Nital
2 to 3% nitric acid in ethanol, a metallography reagent. What it really does to steel, and why it has nothing to do with de-petrification outside Dr Stone.
Nitric Acid
Bacteria turn bat guano into nitrate, step by step, then into dilute acid. The nitrogen chain, HNO₃ chemistry, the Ostwald process, and what episode 1 simplifies.
Papermaking
Senku makes paper in Dr Stone. We explain how alkaline cooking frees cellulose fibers by dissolving lignin, then how the sheet is formed.
Sea Salt
Senku discovers sea salt in Dr Stone: we explain food preservation through osmosis, the vital role of sodium, and the geopolitical history of salt.
Senku's Soap
Fat plus a strong base from wood ash gives soap and glycerol. The steps, the chemistry of saponification, and the weeks of curing Dr Stone skips.
Sodium Carbonate
Senku mentions seaweed-derived sodium carbonate as a soap ingredient: we explain the chemistry of Na₂CO₃, its natural sources, and its shift to industry.
Sulfa Drugs
They mimic PABA and starve bacteria of folic acid, so they stop multiplying. The mechanism, the 1930s history, and why Senku's synthesis is the real stretch.
Wild Foraging
Senku sorts mushrooms and plants in seconds: we explain the rules of mycological identification and the risks of poisoning.
Wine
Senku makes wine in Dr Stone S1E1: we explain alcoholic fermentation, wild yeasts, the natural 16% limit, and how to reproduce it at home.