Letter from Erasmus Darwin to James Watt, 1794/08/17
Darwin writes to Watt to thank him for sending the scientific apparatus, previously requested for obtaining gases.
Derby Augt. 17-94
I should have written to you sooner to thank you for your magnificent apparatus, but knew, that you was gone from home; and as my elaboratory was so out of order, that I was obliged to have a new floor to it, I did not open the apparatus, till yesterday.
Now, as old Nick has much to do in the affairs of this world, I imagine himself or some of his imps have stolen the penult letter you favor’d me with; or, what is more probable, I have laid [it] in some safe place, where I can not now find it. – nevertheless I remember’d it so well as to understand the whole; and think both the joints, and the manner of dropping the water very ingenious, and truly Wattean; but there are two or three things I shall remark. 1. There no perforation between the horizontal and vertical part of the piece immediately connected with the iron-caldron, there is no hole between a and b, which as I suppose to have been a neglect, I shall get made. 2. should there not have been a means of taking airs out of the water-bellows, without disjointing them from the furnace? Now I think it would be convenient to have another pipe to communicate with the air-bellows for the purpose of taking out the air without breaking the joint at x y.
3rdly I think a clear pamphlet should be publish’d of directions how to make airs, and in what to recieve them, etc.
For I now know how to make the carbonic hydrogen-gas, which you describe as being so sickening, but am at a loss to how to get other airs.
From what material has your Birmingham philosophers obtain’d oxygen, cheaper than from manganese?
I hope you will proceed to supply the world with a new Materia Medica, to be drank in by the lungs. And shall be very impatient to recieve the additional part of your apparatus for oxygene gas. The easy production of azote to mix with atmospheric air would be great acquisition for consumptive people, if it can be done, so as to blacken the blood a little more, as you observe, instead of healing ulcers by inducing sickness.
Along with apparatus you have been so kind to send me, there is an iron pot like this, of which I do not know the use.
I have invited all our Derby Philosophers to tea this afternoon, Sunday, to see your apparatus, and I hear a knocking on the door.
Mrs Darwin joins in best respects to Mrs Watt with, dear Sir,
your affect. friend
and obed. serv.