21st May 1835

I set out on a short excursion with Don José Maria Edwards, a pleasant young Anglo-Chilian, to the famous silver Mineral of Arqueros & from thence up the valley of Elque or Coquimbo; passing through a fine alpine country we reached his Fathers mine after it was dark. I enjoyed my nights rest here from a cause the force of which will not be understood in England — there were no fleas! The rooms in Coquimbo swarm with them; at an elevation of about 3000 ft they will not live, & if brought there, as for instance to these mines, they will dye. It can scarcely be the trifling diminution in temperature, 22°, but some other cause which is destructive to these troublesome insects.