264 Chronicles of Science. [ April, 
regard to one body which is likely to be present in the air, and 
which would equally affect the iodide of potassium paper, viz. per- 
oxide of hydrogen, we may state, that M. Houzeau has just 
announced* that he has proved its presence in water condensed 
‘from moist air. 
While on this subject we may notice the statement of M. Jean, 
that carbonic acid under the influence of the electric spark splits up 
into carbonic oxide and oxygen, which latter is strongly ozonized. 
The persistent white vapours obtained by the slow combustion of 
phosphorus in the air, and supposed by Meissner and others to be 
antozone, has been shown by Ozann to consist of nitrite of ammonia, 
thus confirming a statement to the same effect already published by 
Schonbein. 
M. Soret has carried on some researches to ascertain the density 
of ozone, which he considers he has established to be one-and-a-half 
times that of oxygen, viz. 1658. A consideration of the volumetric 
relations of ozone and oxygen would lead to the same conclusion, 
which the author above named considers he has proved by experi- 
ment. 
One unpleasant but important duty of a scientific chronicler is 
often to contradict things he has published before as facts. In our 
last volume (p. 278), we quoted the statement of MM. Moutier and 
Dietzenbacher, that by melting sulphur with small quantities of 
iodine, paraffine, and many other substances, they had converted it 
into a permanently soft and plastic mass. We have now the asser- 
tion of M. Keller,t that after repeating all the experiments of the 
above-named authors, he has never succeeded in producing a plastic 
mass unless the melted sulphur was poured into cold water, in 
which case, as is well known, sulphur is always rendered plastic for 
a time. 
A paper by Dr. Wetherill, “On the Allotropic Modifications of 
Sulphur,’§ may be consulted by those who take an interest im this 
curious subject. 
Professor W. H. Miller has been engaged in determining the 
crystalline forms of the graphitoidal varieties of boron and silicon. 
The latter he has ascertained to crystallize in octohedrons, while 
the crystals of graphitoidal boron appear to- belong to the oblique 
system. 
‘4 A discovery made by M. St. Claire Deville is likely to have 
important technical results. The magnesia obtained by calcining 
the chloride or nitrate of magnesium, when exposed to water, 
becomes converted into a compact crystallized hydrate of great 
* «Comptes Rendus,’ Feb. 26, p. 430. 
+ Ibid., Nov. 27, 1865. 
is Bulletin de la Société Chintique,’ Nov., 1865. 
§ See ‘Chemical News,’ vol. xiii., pp. 89, 97. 
