92 
POPULAR SCIENCE REVIEW. 
dependent upon true chemical affinities, in contradistinction to the view 
which asserts it to he a consequence of the exercise of merely physical 
attractions. 
Siliceous Stalactites. — In a letter to the editor of the Chemical News, Mr. 
Charles F. Burnand describes how siliceous stalactites are sometimes formed 
in the processes carried on in the preparation of super-phosphates.” He 
gives this explanation of the chemical change which produces these stalac- 
tites : — The sulphuric acid used in the process gives rise to the formation of 
fluoride of silicon, which, when it meets the moist steam, decomposes into 
hydrofluosilicic acid and silica, the latter being deposited in the form of sta- 
lactites. — Vide Chemical Neivs, Nov. 8. 
Political Chemists . — The editor of the Moniteur Scientijique, Dr. Quesne- 
ville, publishes a note in a recent number of his j ournal, in which he calls 
attention to the fact that French chemical science has recently been deprived 
of the services of two of its most distinguished devotees : MM. Millon and 
Naquet. The note is as follows : — We have just heard two pieces of bad 
news. The first, which is irremediable, is the death of Millon, that distin- 
guished chemist, whose career was cut short and health impaired by being 
sent to pass the best years of his life in Algeria, because his liberal opinions 
were too advanced to permit his remaining in Paris. The second is the 
arrest of our distinguished colleague M. A. Naquet, Professeur Agrege a la 
Faculte de Medicine, which was doubtless owing to the same cause.” 
Volumetric Petermination of Iron . — Herr Oudemans has recently pointed 
out a method by which the inaccuracies attached to the direct determina- 
tion of iron, by means of hyposulphite of soda (Scherer’s process), are avoided. 
To a solution of ferric oxide, which may contain much free chlorhydric acid, 
are added a few drops of a solution of a cupric salt, and potassic sulphocyanide 
sufficient to render the liquid dark red. A standard solution of sodic hypo- 
sulphite is then added until the red colour has entirely disappeared, which 
point may be observed with great accuracy. The action of the small quan- 
tity of cupric acid consists in causing a more rapid deoxidation of the ferric 
salt. — Vide Zeitschrift fur Analytische Chemie,Vi. 129. 
The Derivatives ofitaconic Acid. — Those who are interested in this important 
subject should consult a splendid memoir which has been recently presented 
by M. Kekule to the Boyal Academy of Belgium. In it M. Kekule criticises 
the researches of M, Swarts,on the derivatives and isomers of this acid. The 
memoir is too long and technical for abstract here j but those who are 
interested in the philosophic development of organic chemistry should consult 
it for themselves. — Vide DInstitut, Oct. 23. 
A new Test for Hyposulphites . — In making some experiments on a delicate 
test for ruthenium, Mr. Carey Lea, the celebrated American chemist and 
philosopher, has found that ruthenium is itself one of the most delicate 
tests of the presence of the hyposulphites. Of course it must be admitted 
as a temporary objection to the new test that ruthenium is extremely rare ; 
but then, on the other hand, we know that once a demand for a substance 
is created the* supply soon follows. Mr. Lea gives the following account of 
the effects of ruthenium on the hyposulphites : When a solution of 
ruthenium is rendered alkaline by ammonia and boiled with h 3 q)osulphite 
of soda, it gradually assumes a rose colour, which passes into a rich carmine ’, 
