Marc Isambard Brunel to Faraday   24 May 1839

Thames Tunnel May 24th May / 39 | 2am

My dear Sir

I am authorised by our Directors to consult you and Mr. Brande respecting the influence of Gases which frequently burst upon us, proceeding evidently from River deposits which have gradually sunk upon us.

We have attended to your direction of a mixture of Ammonia and Lime in the proportion of 1 to 2 as the men can support the emanating vapour; but it happens at almost every high water, that the deleterious waters or fluid soil which contain those Gases, coming in by sudden bursts, and in great quantities, overpower the antidote prescribed.

Our most efficient men, those who operate in the upper part of the shield, are affected with sickness debility and giddiness to a degree that they have left their parts unfinished and in an incomplete state, without being able to account for it, or in some instances, they have been removed almost senseless, and almost beyond recovery.

I may include in the list of those who are equally exposed, the Gentlemen who are my Assistants in this undertaking. I say nothing of myself because I am not so often below nor so long;

The only moderator we find, is that of allowing the ground to rest; but this I have not the option of availing myself of.

I send you some portions of the fluid ground, as it has and does come upon us, besides the black-water which I have sent you before.

Your early attention to this question is particularly desired.

I am my dear Sir very truly yours. | Mc.I. Brunel

Dr. Faraday | &c &c &c