Tardigrades and other "Marvels of Pond Life": A Classic Book on Microscopes by Henry J. Slack

March 18, 2015

Tardigrades and other "Marvels of Pond Life": A Classic Book on Microscopes by Henry J. Slack

 By the mid-19th century central London was the teeming metropolis recognisable from Victorian literature, but its outskirts were not yet urbanised and there was ample opportunity for amateur naturalists to explore local woods, heaths, ponds, and streams, many of which have now disappeared. If you chanced on one of those ponds in 1860 you might have found a man eagerly scanning the shoreline, examining the clarity of the water, dipping his walking-stick in to draw out clumps of algae and aquatic plants, and collecting samples in small bottles. Following him home, you would see him sit down at a microscope and carefully prepare slides from these samples, peering into the eye-piece and taking notes, perhaps with his wife at his side sketching the little world in each drop of water.


That man, Henry J. Slack, was born in London in 1818 and became a businessman and then a newspaperman, serving as writer, editor, and owner of a variety of publications. He was a liberal activist, supporting causes such as the abolition of slavery, higher education for women, and Sunday opening hours for museums and galleries. Most importantly for us, Slack was also "an ardent microscopist" who served as secretary and president of the Royal Microscopical Society and regularly contributed to science periodicals such as Knowledge and Popular Science Monthly (ODNB).


The charming volume depicted here is the first edition of Slack's book Marvels of Pond Life, which charts a full year of his microscopical activities, from January to December, with engaging illustrations provided by his wife, Charlotte. Slack begins with an introduction on how to choose and set up a microscope and what types of light sources to use, and throughout the volume he explains the best ways to locate and prepare different types of samples. Ever the responsible naturalist, he carefully identifies and describes each tiny living specimen, from rotifers and vorticellae to polyps and infusoria, and provides background on their biology and life histories.



Slack's prose is engaging, and perhaps the best example is his passage on the tardigrade, or water bear. These creatures have become famous in recent years for both their adorable appearance and their hardiness, being capable of surviving in environments as extreme as the vacuum of space.


Slack describes his tardigrade specimen as "a little puppy-shaped animal very busy pawing about with eight imperfect legs, but not making much progress with all his efforts... a very comical amusing little fellow he was... each of the eight legs were provided with four serviceable claws, there was no tail, and the blunt head was susceptible of considerable alteration of shape. He was grubbing about among some bits of decayed vegetation, and from the mass of green matter in his stomach, it was evident that he was not one of that painfully numerous class in England - the starving poor".



Slack's book was so popular, thanks to its clear prose, welcoming tone, and detailed illustrations, that it went through at least four editions by the end of the century and is still considered one of the classics of Victorian popular science writing. Below, more illustrations from our copy of Marvels of Pond Life.








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  • For more on tardigrades, see this piece in Wired, and check out the videos below, from UNC Chapel Hill and SciShow.