José María Velasco’s 1894 painting Rocks is the size and format of a grand portrait but, instead of a socialite in taffeta or tails, it portrays a huge reddish-brown rock formation. It isn’t even a very special outcrop, rather the kind of shapeless mass you might encounter on any mountain walk. That’s the point.
Velasco is a scientific artist who worked at a time when the Americas were a wonderland of discovery. He identified a new species of salamander that lives in a lake near Mexico City, only one of the many finds, living and fossilised, uncovered in his era across the New World. In 1902, the first Tyrannosaurus rex fossil was excavated in Montana; in 1909, very early life forms were found preserved in Canada’s Burgess Shale. Most important of all, back in the 1830s, Charles Darwin found the first evidence for evolution in the rainforests and rocks of Brazil and Peru.

So behind the ordinariness of Velasco’s rocks is the discovery that Earth’s fabric is made by continuous processes over many millions of years – not by sudden biblical catastrophes. These stones contain a secret, he says, and it’s worth knowing. The people in Rocks on the Hill of Atzacoalco, painted in 1874, look as if they’re seeking out such knowledge. They walk steadily up a path, the women in long skirts and a man in a white suit, with a parasol against the sun. But these little figures are dwarfed by the rocks looming over them, embedded with white crystal, stark as bones in the rusty-red rock. Velasco is more interested in the rocks than the people. Can’t you see, the painting asks, how marvellous these ancient formations are?
The paintings glow with the sense of a continent growing in time and space through scientific discovery. In two spectacular panoramic views of the Valley of Mexico, he paints snowcapped volcanoes floating above an almost nondescript populated plain, all squeezed into a single panorama, assimilable in a single sweeping gaze.
Trained in several sciences before he opted for art, Velasco applies an objective eye to a world poised between antiquity and change. His fascination with nature doesn’t stop him recording Mexico’s industrialisation with equal curiosity. A goatherd tends his flock next to a new factory, its shiny metal pipes rendered with the same relish as the light green foliage in which the goatherd moves. Another painting is called The Textile Mill of La Carolina, Puebla, but this objectively depicted, low, white industrial structure is overlooked by a volcano. Velasco’s volcanoes are satisfyingly cone-shaped, like scientific toys. Just add baking powder and vinegar.
He’s a subtle and pellucid colourist, bringing out blue-green hues in leaves, lingering on an emerald-coloured cactus and the azure of desert skies. His nature studies are truly lifelike. A painting of thick, velvety mafaffa leaves is both natural history and a passionate response to greenness.
Yet if a landscape is brown or desert-yellow, he shows it. His 1878 painting The Baths of King Nezahualcoyotl is a determinedly unromantic view of ancient remains: Velasco insists archaeology is seeing the magic in broken fragments, not Indiana Jones adventures. He shows hard-to-decipher chunks of masonry and a flight of ancient steps in his precise depiction of this pre-Columbian site.

It feels mean and even redundant to say Velasco is a bit dull. This admirable artist is, after all, proudly that. He cools the temperature with every smooth brushstroke, resisting the sublime effects that many other 19th-century landscape artists in the Americas laid on with a shovel. Not for him the romantic excesses of the US’s Hudson River artist Frederic Church, who painted the volcano Cotopaxi erupting in Ecuador in a heavy metal concerto of fire. Geological structures are not there to awe us, says Velasco. They contain the scientific story of Earth.
He is boring, though. The devil has all the best tunes and Mexico’s visual history is replete with them. The Aztec empire on the eve of its Spanish conquest practised human sacrifice, made art with skulls, feathers, turquoise and jade, worshipped dangerous and disturbing gods. In Mexico’s modern art such traditions have been enthusiastically embraced, from José Guadalupe Posada’s carnivalesque skeleton prints to Frida Kahlo’s personal mythology of pain.
The National Gallery itself seems a little unsure about Velasco’s appeal, stressing in the catalogue and wall chronology that he taught Kahlo’s husband, Diego Rivera. It boasts this is “the first ever exhibition dedicated to a historical Latin American artist at the National Gallery”. But so what? Mexico’s art, from its chunky Mesoamerican monsters to its modern surrealisms, doesn’t lack attention. Right outside the National Gallery, you can see Teresa Margolles’s recreation of an Aztec skull tower on the fourth plinth. Velasco’s work is different from such art simply because his eye is more European, academic and rationalist. This is a Mexico tamed.