The following letters to Sir H. Roscoe and Dr. Tyndall were written during this tour:—­]

Le Puy, Haute Loire, France, July 17, 1873.

My dear Roscoe,

Your very kind letter reached me just as I was in the hurry of getting away from England, and I have been carrying it about in my pocket ever since.

Hooker and I have been having a charming time of it among the volcanoes of the Auvergne, and we are now on our way to those of the Velay and Vivarrais.  The weather has been almost perfect.  Perhaps a few degrees of temperature could have been spared now and then, especially at Clermont, of which somebody once said that having stayed there the climate of hell would have no terrors for him.

It has been warm in the Mont Dore country and in the Cantal, as it is here, but we are very high up, and there is a charming freshness and purity about the air.

I do not expect to be back before the end of September, and my lectures begin somewhere in the second week of October.  After they commence I shall not be able to leave London even for a day, but I shall be very glad to come to the inauguration of your new buildings if the ceremony falls within my possible time.  And you know I am always glad to be your guest.

I am thriving wonderfully.  Indeed all that plagues me now is my conscience, for idling about when I feel full of vigour.  But I promised to be obedient, and I am behaving better than Auld Clootie did when he fell sick.

I hope you are routing out the gout.  This would be the place for you—­any quantity of mineral waters.

Pray remember me very kindly to Mrs. Roscoe, and believe me, ever yours very faithfully,

T.H.  Huxley.

Hotel de France, Baden-Baden, July 30, 1873.

My dear Tyndall,

We find ourselves here after a very successful cruise in the Auvergne and Ardeche, successful at least so far as beauty and geological interest go.  The heat was killing, and obliged us to give up all notion of going to Ursines, as we had at first intended to do.  So we turned our faces north and made for Grenoble, hoping for a breath of cool air from the mountains of Dauphiny.  But Grenoble was hotter even than Clermont (which, by the way, quite deserves its reputation as a competitor with hell), a neighbour’s drains were adrift close to the hotel, and we got poisoned before we could escape.  Luckily we got off with nothing worse than a day or two’s diarrhoea.  After this the best thing seemed to be to rush northward to Gernsbach, which had been described to me as a sort of earthly paradise.  We reached the place last Saturday night, and found ourselves in a big rambling hotel, crammed full of people, and planted in the bottom of a narrow valley, all hot and steaming.  A large pigstye “convenient” to the house mingled its vapours with those of the seventy or eighty people who ate and drank without any other earthly occupation that we could discern during the three days we were bound, by stress of letters and dirty linen, to stop.  On Monday we made an excursion over here, prospecting, and the air was so fresh and good, and things in general looked so promising that I made up my mind to put up in Baden-Baden until the wife joins me.  She writes me that you talk of leaving England on Friday, and I may remark that Baden is on the high road to Switzerland.  Verbum sap.