[So far back as 1870 a committee had been appointed by the British Association, and reported upon the conditions under which they considered experiments on living animals justifiable.  In the early spring of 1875 a bill to regulate physiological research was introduced into the Upper House by Lord Hartismere, but not proceeded with.  When legislation seemed imminent Huxley, in concert with other men of science, interested himself in drawing up a petition to Parliament to direct opinion on the subject and provide a fair basis for future legislation, which indeed took shape immediately after in a bill introduced by Dr. Lyon Playfair (afterwards Lord Playfair), Messrs. Walpole and Ashley.  This bill, though more just to science, did not satisfy many scientific men, and was withdrawn upon the appointment of a Royal Commission.

The following letters to Mr. Darwin bear on this period:—­]

4 Marlborough Place, January 22, 1875.

My dear Darwin,

I quite agree with your letter about vivisection as a matter of right and justice in the first place, and secondly as the best method of taking the wind out of the enemy’s sails.  I will communicate with Burdon Sanderson and see what can be done.

My reliance as against —­ and her fanatical following is not in the wisdom and justice of the House of Commons, but in the large number of fox-hunters therein.  If physiological experimentation is put down by law, hunting, fishing, and shooting, against which a much better case can be made out, will soon follow.

Ever yours very faithfully,

T.H.  Huxley.

South Kensington, April 21, 1875.

My dear Darwin,

The day before yesterday I met Playfair at the club, and he told me that he had heard from Miss Elliott that I was getting up what she called a “Vivisector’s Bill,” and that Lord Cardwell was very anxious to talk with some of us about the matter.

So you see that there is no secret about our proceedings.  I gave him a general idea of what was doing, and he quite confirmed what Lubbock said about the impossibility of any action being taken in Parliament this session.

Playfair said he should like very much to know what we proposed doing, and I should think it would be a good thing to take him into consultation.

On my return I found that Pfluger had sent me his memoir with a note such as he had sent to you.

I read it last night, and I am inclined to think that it is a very important piece of work.

He shows that frogs absolutely deprived of oxygen give off carbonic acid for twenty-five hours, and gives very strong reasons for believing that the evolution of carbonic acid by living matter in general is the result of a process of internal rearrangement of the molecules of the living matter, and not of direct oxidation.

His speculations about the origin of living matter are the best I have seen yet, so far as I understand them.  But he plunges into the depths of the higher chemistry in which I am by no means at home.  Only this I can see, that the paper is worth careful study.