145 
August 24, 1872.] THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
of these two acids, and to transform them into amido- 
acids, with the object of making an artificial cystine; 
and the results arrived at will shortly be communicated 
to the Society. 
TINCTURE OP FERRIC CHLORIDE. 
BY It. llOTHElt. 
The numerous vital objections to the officinal process 
induced the writer to supplant the nitric acid of the for¬ 
mula by the use of potassium chlorate. This alteration 
removed one of the most disagreeable and unsatisfactory 
agents ever associated with this preparation. The un¬ 
certain action of nitric acid, together with its various 
other defects in this connection, becomes more thoroughly 
apparent when compared with the unqualified success 
attending the action of potassium chlorate. 
In the attempt to remedy the defective method of dis¬ 
solving the iron, the w’riter resorted to the use of sodium 
chloride by double decomposition with a mixture of 
ferric sulphate and chloride and the interposition of alco¬ 
hol ; then to the employment of ferrous sulphate and 
calcium chloride; after this the trial by double decom¬ 
position between ferrous sulphate and sodium chloride 
in presence of alcohol was made. 
Now when atomic proportions of ferrous sulphate, 
sodium chloride, chlorhydric acid and potassium chlorate 
are mixed, with a view to obtain ferric chloride and 
sodium sulphate, and the mixture is then treated with 
alcohol, a yellowish red solution and a yellowish granu¬ 
lar precipitate are obtained. The solution will most 
usually contain only two-thirds of the intended amount 
of ferric chloride, whilst the remaining one-third of the 
iron is carried down with' the sodium sulphate in a pecu¬ 
liar state of combination, probably as basic sulphate or 
oxy-chloride. By washing the precipitate with water 
most of the sodium sulphate, together with some iron, 
are dissolved, but most of the iron remains in the residue 
insoluble in chlorhydric acid. By the above reaction it 
seems very probable that only two-thirds of the ferric 
sulphate is decomposed by the sodium chloride. 
The trial with calcium chloride is very satisfactory in 
regard to completeness of decomposition, the only draw¬ 
back is the bulky nature of the calcium sulphate, which 
must be carefully washed to secure the whole of the iron. 
This is attained by pressing the hot mixture through 
muslin; the process is very expeditious, and could be 
recommended were it not for the difficulty of handling 
the precipitate. 
The double decomposition between the ferrous sul¬ 
phate and sodium chloride, in presence of alcohol, results 
in a green solution and a white precipitate ; the green 
solution when treated with chlorhydric acid and potas¬ 
sium chlorate, yields a solution which corresponds only 
to two-thirds of the original amount of ferrous sulphate, 
the remainder is precipitated as ferrous sulphate 
along with the resulting sodium sulphate and undecom¬ 
posed chloride. From this it is evident that only two- 
thirds of the ferrous sulphate is decomposed by anatomic 
equivalent of sodium chloride. 
It was also noticed that in the alcoholic solution of 
ferrous chloride, a certain proportion of water was 
necessary to cause the decomposition of the potassium 
chlorate, whereas, in case of a deficiency, no oxidation 
would take place through the chlorate. 
But originally the writer noticed that metallic iron 
dissolved more readily in moderately diluted acid ; how¬ 
ever, as the solution always proceeds immoderately slow, 
and it was difficult to determine when all of the acid had 
been saturated, it was found that the process would be 
much facilitated and hastened by using only the proper 
quantity of iron to be dissolved, and for this purpose 
emulovimr the whole amount of the acid at once. 
Finding that the ordinary forms of iron were in¬ 
variably too coarse for rapid solution, the writer resorted 
to the pulverized iron of the market; this is not the iron 
reduced by hydrogen, but still a very fine powder, and 
and can be bought at one-sixth the price of the former. 
It naturally dissolves very rapidly, and, therefore, in case 
of necessity, the tincture can be prepared with it in a 
very short time by the following process:— 
Take of Iron in fine powder . . . 1300 grains. 
Chlorhydric acid sp. gr. 1.16. 17J troy ounces. 
Potassium chlorate in pwdr. 475 grains. 
Strong alcohol. 2 pints. 
Water sufficient. 
Dilute the acid with the w'ater to the measure of two 
pints, then gradually add the iron in small quantities at 
a time; w r hen complete solution is effected, add the 
potassium chlorate; stir until dissolved ; let stand a few 
minutes and then mix the alcohol with the solution 
w r hile yet warn, and filter.— The Chicago Pharmacist. 
ORGANIC CHEMISTRY AND THERAPEUTICS.* 
BY A. W. HOFMANN. 
It has been said that chemistry is the most useful of 
all the sciences, and the assertion is not an exaggerated 
one. Where indeed in the whole domain of the arts and 
industry is the field which has not been made more pro¬ 
ductive by the powerful influence of chemical research, 
and what resources for our daily wants do we not owe 
to the development of this science F But, however 
powerful may be the direct influence which chemistry, 
in giving us the dominion over matter, has exercised and 
still exercises every day upon our well-being, it has con¬ 
tributed nearly as much to the progress, of civilization by 
the revolution which it has provoked in all branches of 
science, and in the region of thought; in one word, in our 
entire life. In the short space of time accorded to me I 
should be unable to indicate even in a superficial manner 
how much chemistry has contributed to the present 
state of things; considering the learned body whom I 
am addressing, I might enumerate the services chemistry 
has rendered to medical science ; but the subject would 
be too vast. I will be content with noticing the advan¬ 
tages which therapeutics has . derived and wall derive 
from the development of organic chemistry. 
Since only organic chemistry is to be spoken of, it will 
be w'cll to commence by defining the extent of this por¬ 
tion of the science; the more so, as its extent is much 
modified with the lapse of time, and that, even now, all 
chemists are not in accord as to the limits they ought to 
assign to it. It requires but a superficial study of chemi¬ 
cal phenomena to see how few simple bodies possess the 
power of .combining with each other in a great number 
of proportions. Hydrogen does not combine with chlorine, 
bromine or iodine in more than one proportion. This 
same hydrogen forms with oxygen two combinations, 
and two also with sulphur. Phosphorus and arsenic are 
remarkable for the facility with which they combine 
with oxygen, but they only form with it two combina¬ 
tions. In an analogous manner, sulphur and phospho¬ 
rus combine with chlorine in two proportions only, and 
it is rarely that an element forms with another three or 
four combinations; there are, however, three oxides of 
antimony and of iron, and four of lead and of manganese 
known. Nitrogen unites with oxygen in a still greater 
number of proportions,—the number of its well defined 
oxvgen compounds being not less than five, but these 
compounds are an exception to the usual law. 
But there are two elements which, in this respect, are 
distinguished from all. others, carbon and hydrogen ; 
their combinations are innumerable. This is not saying 
that the known hydrocarbons are so numerous, —chemists 
* Lecture delivered at the Medico-Chirurgical Institute of 
Berlin 
