Manchester, 5 October 1866 

Dear Moor, 
T am tickled by your naivety in having bills outstanding against 
you without knowing the amount; however, it’s lucky the 

4 As regards - > P. Trémaux, Origine et transformations de Vhomme... - © See this 
volume, pp. 320-21. - 4 mutability of species 

difference was no bigger and the good baker was at hand. So that 
you can repay the sum in question to that excellent man at once 
and thus preserve your credit, I am enclosing £5 I/F 59667, 
Manchester, 30 January 1865, for you, and am also returning the 
bill now settled. 

Ad vocem* Trémaux. When I wrote to you, I had admittedly 
only read a third of the book, and that was certainly the worst part 
(at the beginning). The second third, the critique of the schools, is 
far better; the third, the conclusions, very bad again. The man 
deserves credit for having emphasised the effect of the ‘soil’ on the 
evolution of races and logically of species as well more than had 
previously been done, and secondly for having worked out more 
accurate (though, in my view, still very one-sided) views on the 
effects of crossing than his predecessors. In one respect, Darwin is 
also right in his views on the effect crossing has in producing 
change, as Trémaux incidentally tacitly acknowledges, in_ that, 
when it suits him to do so, he also treats crossing as a means of 
change, even if ultimately as one that cancels itself out. Similarly, 
Darwin and others have never failed to appreciate the effect of the 
soi], and if they did not especially emphasise it, this was because 
they had no notion of how the soil exerts an influence—other 
than that fertility has a favourable and infertility an unfavourable 
effect. And Trémaux is little the wiser about that either. The 
hypothesis that, as a general rule, the soi) favours the development 
of higher species to the extent that it belongs to more recent 
formations, sounds exceedingly plausible and may or may not be 
correct; however, when I see the ridiculous evidence with which 
Trémaux seeks to substantiate it, of which °/;) is based on 
erroneous or distorted facts and the remaining '/,) proves nothing, 
I cannot but extend the profound suspicions I have of the author 
of the hypothesis to the hypothesis itself. But when he then goes 
on to declare that the effect of the soil’s greater or lesser age, 
modified by crossing, is the sole cause of change in organic species 
or races, I see absolutely no reason to go along with the man thus 
far, on the contrary, I see numerous objections to so doing. 

You say that Cuvier also criticised the German natural 
philosophers for their ignorance of geology when they proclaimed 
the mutability of species, and yet they were proved right.’ At 
that time, however, the question had nothing to do with geology; 
but if someone puts forward a theory of the mutability of species 
based on geology alone and makes such geological howlers in it, 

@ As regards - > See previous letter (p. 322). 

falsifies the geology of whole countries (e.g., Italy and even 
France) and takes the rest of his examples from countries of 
whose geology we are as good as totally ignorant (Africa, Central 
Asia, etc.), then that is altogether a different matter. With regard 
to the ethnological examples in particular, the ones that concern 
countries and peoples which are generally known are almost 
without exception erroneous, either in their geological premisses 
or in the conclusions drawn from them-—and he completely 
ignores the many contrary examples, e.g., the alluvial plains in 
Central Siberia, the enormous alluvial basin of the River Amazon, 
all the alluvial land southward from La Plata almost to the 
southern tip of America (east of the Cordilleras). 

That the geological structure of the soil is closely related to the 
‘soil’ in which everything grows is an old idea, likewise that this soil 
which is able to support vegetation influences the flora and fauna 
that subsist on it. It is also true that this influence has as yet been 
scarcely examined at all. But it is a colossal leap from there to 
Trémaux’s theory. At all events, he deserves credit for having 
emphasised this previously neglected aspect, and, as I said, the 
hypothesis that the soil encourages evolution in proportion to its 
greater or lesser geological age, may be correct within certain limits 
(or again it may not), but all the further conclusions he draws I 
consider to be either totally mistaken or incredibly one-sided and 
exaggerated. 

I was very interested by Moilin’s book,* particularly for the 
results the French have obtained by vivisection; it is the only way 
to ascertain the functions of certain nerves and the effects of 
interfering with them; these fellows appear to have taken the art 
of animal-torture to a very high level of perfection; and I can very 
well understand the hypocritical fury of the English against 
vivisection; these experiments no doubt came as a most unpleasant 
surprise to many of the comatose gentlemen here and overturned 
many of their speculations. Whether there is anything new in the 
theory of inflammations, I am in no position to judge (I intend 
giving the book to Gumpert); this whole new French school does, 
however, appear to have a certain free-and-easy character, making 
big claims and being rather less scrupulous with evidence. As 
regards medicines, it contains nothing that any competent German 
doctor does not also know and accept; Moilin just forgets that 
1. one is often obliged to choose the lesser evil, medicine, in order 
to get rid of the greater, namely, a symptom which in itself 

a J. A. Moulin (le docteur Tony), Legons de médecine physiologique. 

represents a direct danger, in exactly the same way that by 
surgery one destroys tissues where there is no alternative, and 
2. that one does have to stick to the medicines for as long as one 
has nothing better. As soon as Moilin can cure syphilis with his 
electricity, mercury will soon vanish, but scarcely until then. 
Incidentally, no one can go on telling me that only the Germans 
can ‘construct’ systems, THE French BEAT THEM HOLLOW AT THAT. 
Kindest regards. 

Your 
F, E.