I had also a sad letter from my friend Arbuthnot on his return from France, but it was written in so melancholy a strain on his own situation and that of his wife and family, that it has often made my heart ache to read it. By Lord Loughborough’s interest he got an appointment in Ireland under the Linen Board,[73] which carried him to that country, where he lived but a few years. I lost in him by far the most agreeable friend I was ever connected with. At this time I was much engaged in making a variety of experiments in expelling gaseous fluids from specimens of soils, the results of which were afterwards published in ‘The Annals of Agriculture.’ As I met with some difficulties I wrote to Dr. Priestley, stating them, and begging information. He very liberally and politely answered all my enquiries, encouraging me to proceed with my trials, and I received several interesting letters from him. ‘Birmingham: Dec. 12, 1781. ‘Dear Sir,—If I had any remarks or hints respecting the subject of your experiments, I should certainly with much pleasure have communicated them long ago. I meant, indeed, to have made a few more experiments on the growth of plants in the course of the last summer, but the weather was so bad, and the sun shone so little, that I dropped the scheme. All I can do, therefore, in return for your _facts_, is to mention one that I have lately observed. I readily convert _pure water_ into _permanent air_, by first combining it with quicklime, and then exposing it to a strong heat. The weight of the air is equal to the weight of water, and no part of the water is turned into _steam_ in the process. During the whole of it, a glass velum, interposed between the retort and the recipient for the air, remains quite cool and dry. The air I procure in this manner is in part _fixed air_, but the bulk of it is such as a candle would hardly burn in it, but is such as I should imagine would be the best for plants, which would purify it and render it fit for respiration. And as this kind of air would be yielded in great abundance by volcanoes, from calcareous matter in the earth; such was perhaps the original atmosphere of this earth, which according to the Mosaick account (which you must allow me to respect) had plants before there were any land animals. ‘This letter I fear is hardly worth sending you; your objects and mine are so very different, though now and then coinciding; but mine have seldom any practical uses, at least no immediate ones, whereas yours are highly and immediately beneficial. Wishing you the greatest success, and wishing you and all philosophers joy of the near prospect of peace, ‘I am, yours sincerely, ‘J. PRIESTLEY.’ This year’s memoranda: ‘Wrote “Emigration,” an ode.’