6 
I^TR0DUCT10N. 
pamphlet que j’enverrai a tous les geologues d’Europe et d’Amerique, pour decliner toute responsabi- 
lite et participation k ce travail. 
Quant aux specimens sans memoranda de localites et parmi lesquels vous me dites avoir trouve 
des Ammonites, Gryphxa incurva et Plagiostoma, ils ne peuvent pas appartenir a ma collection faite sur 
la route du Lieut. Whipple, car je n’y ai pas trouvA de pareils fossiles; et jo ne m’explique leur pre- 
sence parmi les specimens renvoyes de France , que par un melange de paquets qui aura eu lieu a 
Salins lors de mon arrivee d’Am6rique; dans le triage et le demenagement que j’ai fait de toutes mes 
collections , precisement a ce moment-la. Ces specimens proviennent probablement des environs de Sa- 
lins, car ce sont les seuls dans mes collections auxquels je ne mets pas de memoranda de localites. 
J’envoie une copie de cette lettre au Lieutenant Whipple et je me reserve de la publier le cas 
ech6ant. 
J’ai I’honneur de vous saluer. Votro serviteur 
(Signe) JULES MARCOU. 
p. s. — Suivant votre desir je vous envoie franco par la poste mes dernieres publications « On 
American Geology*. 
I will add that my note-books were written in pencil, with abbreviations and conventional signs, 
and in the French language , and that I know nothing of Mr. Blake, either personally, or as a man 
of science. 
The letter above cited is the only communication I have received from this savant, who, I 
have been told, was the geologist of the first expedition commanded by Lieutenant B. S. William- 
son to survey the most practicable pass between the Rio Colorado and the southern part of Cali- 
fornia. But he did not accompany the expedition in the exploration of the Mohavee river; and he 
is said further to have never even crossed the Mississippi river , having made his trips to and from 
California by the Panama route. 
As an illustration of Mr. Blake’s desire to „ regard ray wishes", as he expresses himself dis- 
posed to do in the letter with which he honoured me; 1 have learned since from good authority 
that the Secretary of War, in accordance with the advice of Mr. Blake, refused to put in the quarto 
edition my Resume with some additional notes I had forwarded for that purpose; Mr. Blake having 
placed in their stead a translation of my note-books, with a French version on the opposite column; 
a translation and version necessarily full of faults, errors, and falsifications, which I must entirely 
refuse to acknowledge as my production. 
Not satisfied with an act so wanting in courtesy toward me, Mr. Blake read a paper, at the 
Meeting of the American association for the advancement of science, held at Albany in August 1856, 
entitled ,,On a geological Map of America made in Europe’-^-, which has since been published in Silliman's 
Journal, under another title; „ Review of a Portion of the geological Map of the United States and British 
Provinces, by Jules Marcou®. In this article Mr. Blake insinuates that my map is merely a com- 
pilation, that it was made in Europe, not even hinting that I have visited the Rocky Mountains; 
and that I have not known how to make a faithful use of the means in my power for the execution 
