Letter from Erasmus Darwin to James Watt, 1795/11/21

Darwin writes to Watt concerning the health of Darwin’s daughter, Emma and various scientific matters.

Derby Nov. 21-95

My dear friend,

I was much obliged to you for the kind attention, you shew’d me, in sending some pounds of manganese, and for the remainder since; and shall be obliged to you to direct your people to send my account all together, as I can not readily find it piecemeal; and to call on me, if any of them comes this way for the money, if I do not soon find an opportunity to send it.

My daughter Emma is better, but has not taken the oxygene so regularly, as she ought to have done, owing in part to my absence from home; but I intend to manage it better; and if it serves her, I will send you a further history – she takes also 2 grains of opium a day to prevent or lessen a nervous cough, which she has returns of daily about the same hour, but which is now much lessen’d by the use of the opiate; one grain of which is given on going to bed and another about five in the morning; as her cough had for many weeks return’d about seven in the morning. She also takes bone-ashes, soda phosphoreta, and powder of bark of each ten grains twice a day, so that the oxygen gas is but a part of the process.

The disease I believe to be “softness of bones” and her quick respiration owing to the ribs of one side not being sufficiently rigid. – but why do I tell you all this stuff? – I do it, because you have been so good as to interest yourself about her health.

Dr Menish of Chelmsford writes me word, that a hard brick weighs a great deal more after it is burnt than when in its dry state, before it is burnt. – does glass acquire oxygene? – I should suppose so from the red lead, and manganese, which so readily induce clays and flint to vitrify. – might not a measure of high degrees of heat be thus made, by weighing certain vitrescent mixtures, or clays, after and before they experience the fire?

The new theory of fever in my next volume will take up 80 pages, I dare say; and will I hope amuse you. It shews, why the capillary vessels of the skin act too violently, producing h(eavy?) perspiration, and great absorption, for 3 or (4) weeks together in continued fevers with weak p(ulse) and why at the same time the heart and arteries act all the while feebler a great deal than natural, tho’ their pulsations are quicker.

Now I grow old and not so well amused in common society, I think writing books an amusement, – I wish you would write books, instead of having those confounded headachs, which you complain of! Adieu. Mrs Darwin begs to join with me in best wishes and most respectful compliments to yourself and Mrs Watt,

from your sincere and affect. friend

E Darwin

I hope our friend Boulton has not much return of his gravelly complaint, somebody lately told me he was worse, which grieved me much.

I have often thought of a mouth-piece for breathing with two valves, but never could please myself. Mudge made one with a pea for a valve, I have forgot how, but I remember it was too far from the mouth, and therefore left some air to be respired over again.