SCIENTIFIC SUMMARY. 
93 
7. It is cheaper than ordinary powder in the proportion of 30 to 31. The 
prices by weight are the same, but as it has been found that 76^ grains of 
Neumeyer’s have the same explosive force as 79^ grains of ordinary powder, 
the above proportion may easily be deduced. — Vide Berg- und hiittenman- 
nische Zeitung , No. 36, 1866. 
The Synthesis of Besor cine . — Herr Korner has been engaged in some re- 
searches upon resorcine. To those who have -waged war against chemical 
technicalities, the following paragraph may be of interest. Ilerr Korner 
starts with benzol ; converts this into binitrobenzol ; from this prepares 
paranitroaniline ; transforms the nitrate of this base into nitrate and then 
sulphate of paradiazonitrobenzol. Under the influence of hydriodic acid this 
salt gives paraiodonitrobenzol, which, with tin and hydrochloric acid, is 
reduced to paraiodaniline. From the nitrate of this base the sulphate of 
paradiazoiodobenzol is formed. This salt decomposed by boiling water gives 
a new acid, paraiodophenic acid. This is solid and well crystallised ; its 
most remarkable property is to give, under the influence of fused potash, a 
crystallised combination which is the inferior homologue of orcine described 
by MM. Hlasiwitz and Barth under the name of resorcine. Herr Korner hopes 
to show that phloroglucine and pyrogallic acids are trihydroxylic derivatives 
of benzol, and that, by starting from toluol, he will effect the synthesis of 
orcine. 
The Detection of Iodine . — Mr. Carey Lea, the celebrated American photo- 
grapher, has suggested a new and useful test for the presence of iodine. It 
states that, while engaged in testing for iodine, it occurred to Mr. Lea that 
the facility with which that body is eliminated from its hydrogen and me- 
tallic combinations by chromic acid would make the latter substance a 
valuable means of bringing about the starch reaction, and a few experi- 
ments completely confirmed this view. If, for example, an extremely dilute 
solution of iodide of potassium, such that the addition of nitric acid and 
starch produces no perceptible effect, is taken, the further addition of a 
single drop of very dilute solution of bichromate of potash will instantly 
bring about the characteristic reaction. When chlorhvdric acid is substi- 
tuted for nitric, the effect of the bichromate is (as was to be expected) still 
more marked. The test has the full delicacy at least of the chlorine test, 
with this great advantage that an excess of the reagent does not prevent 
the reaction. 
Wine and Wine Sic7mess. — The results of M. Pasteur’s valuable researches 
on this subject may thus be summarised : — 1. That the dangerous changes 
which occur in wine arise from causes which are mixed up with those to 
which fermentation is attributed. 2. That the heating of ordinary wine to 
the extent of 50° centrigrade is sufficient to kill all microscopic vegetation, 
or the ferments which produce them : fermentation and all other dangers 
due to these causes being thus arrested or prevented. 3. The application 
of the amount of heat indicated does not in any way effect the flavour or 
the colour of wine, and assures brightness. 4. Wines which have been sub- 
mitted to such temperature appear capable of being kept indefinitely in 
closed vessels. 5. When exposed to the air, such wines, it is true, may 
become affected after a certain lapse of time ; but this is in consequence of 
the air supplying them with the living germs of those ferments which they 
previously lost by the action of heat. 
