FACTS AND OBSERVATIONS, 
589 
from one and the same carbide of hydrogen^ the as yet hypo¬ 
thetical combination triphenylene.— Fopular Science Review. 
The Relation of the Osseous Medulla to the 
Blood. —The British Medical Journal, in abstracting a re¬ 
cent paper^ by Herr Neumann, in the German Centralblatt, 
calls attention to the fact that Neumann’s startling theory 
that the marrow developes blood-cells, has received confirma¬ 
tion by the observations of M. Bizzozero. Among other 
things, this observer says that the condition of the marrow in 
the bones of frogs in winter, as compared with summer, 
furnishes an important argument in favour of the theory that 
marrow is a blood-gland. In winter, the white corpuscles in 
the blood of the frog are not half so numerous as they are in 
summer ; and in winter the marrow consists almost entirely 
of fat-cells, whereas in summer it contains hardly anything 
but lymphoid cells. He examined the costal marrow and 
the spleen in five cases of death from typhus fever, and ob¬ 
served in both structures an enormous increase of cells 
containing blood-corpuscles.— Ibid. 
Chromic Acid in Therapeutics. —In the Bulletin 
General de la Therapeutique, Dr. E. Magitot recommends 
chromic acid as an application to various affections of the 
buccal mucous membrane—such as all forms of stomatitis ; 
and particularly the different kinds of gingivitis, from that 
connected with dentition (as when, for example, it attends 
the eruption of a wisdom tooth), to ulcerative stomatitis. 
Aphthae, and divers other ulcerations of the buccal mucous 
membrane, are also, he says, rapidly modified by this agent. 
But the afi:ection for whjch he specially recommends the acid 
is ^^alveolo-dental osteo-periostitis.”— Ibid. » 
Coal from Sea-weed. — Some time since, says the 
Annales de Genie Civil, the practice was introduced of con¬ 
verting marine algae by calcination into an excellent coal 
superior to ordinary wood charcoal for filtering water, disin¬ 
fecting sinks, polishing glass and correcting the acidity and 
decolorising wines,—also for precipitating and decolorising 
vegetable alkaloids. Until recently no value was attributed 
to the marine algae—to-day they are an important article of 
commerce in several islands.— Ibid. 
The Varieties of Dogs. —Dr. John Edward Gray has 
written a paper on the varieties of dogs in the Annals of 
Natural History. In reference to that kind of variation, 
which he thinks ought to be looked upon as abnormality, the 
author points out the following four types:—I. The short 
