PREPARATION OF IRON. 
303 
ART. LXXXV. — NOTE UPON THE PREPARATION OF IRON 
REDUCED BY HYDROGEN. 
By MM. E. Soubeiran and Dublaiw. 
Iron reduced by hydrogen, of which the employment 
was proposed by M. Quevenne, has been adopted in medi- 
cal practice. It is now prepared in quantity for the use of 
the hospitals of Paris. It would appear at first sight that 
nothing could be more simple than to bring about the re- 
duction of the oxide of iron, by a current of hydrogen gas ; 
but when it comes to the trial, considerable difficulty is 
encountered. It is well known that no one yet has been 
able to arrive at results as satisfactory as those obtained by 
our associate Quevenne, who has applied to the study of 
this operation that patient and enlightened intelligence with 
which we all know he is endowed. Unfortunately he has 
not communicated all of his observations, and those have 
been forced, who have wished to prepare the reduced iron, 
to make a host of attempts, that have not always been suc- 
cessful. M. Thiebierge has published recently an interest- 
ing note on this subject ; his ingenious apparatus will be 
useful to those who wish to prepare small quantities of the 
article, but does not answer the purpose in the more ex- 
tended manufacture of it. 
The reduced iron intended for medicinal use should be 
presented in the form of a minutely divided powder. The 
essential condition of success in the operation, consists en- 
tirely in the temperature, which, if not sufficiently high, the 
reduction does not take place ; but if too high, the iron is 
reduced, but becomes agglutinated in ductile laminae and 
the operation fails. To heat properly is then the principal 
object that should be proposed ; to multiply the points of 
contact between the oxide of iron and the hydrogen is a 
second condition that it is necessary to fulfil ; less essential 
