SCIENTIFIC SUMMARY. 
275 
Vascular System in Plants. 
Observations on Rapliides. 
Literature of Rapliides. 
Medical Sciences — 
Bacteria in the Blood of Persons labouring under Typhoid Fever. 
The Structure of Cartilage. 
Structure of the Kidney. 
A new compressiorium of the reversible kind has been devised by Mr. 
Slack and Messrs Smith and Beck, and manufactured by the latter. It 
is, in principle, simply an aquatic box, which by means of a screw can 
have the two surfaces of glass approximated without their undergoing any 
rotation. One of its advantages, and certainly no mean one, is that the 
glasses can be removed, so that the observer can employ either thick 
pieces for compressing large objects under a low power, or conversely thin 
plates for higher objectives. It is a decided improvement on the instrument 
suggested by Professor De Quatrefages. 
MINERALOGY. 
Presence of Titanium in Pig Iron. — The small red cubical crystals 
which are found in the hearths of old blast-furnaces were supposed by 
Wollaston to be titanium, but were afterwards shown by Wohler to be a 
compound of nitride and cyanide of titanium. The subject has been 
taken up for investigation by Mr. Edward Riley, F.CbS., who finds that 
titanium is abundant in iron, and that as it is, according to' his researches, 
also found in clay, its presence in the former is most probably due to the 
employment of the clay-iron ore. Hitherto titanium held a very low 
place in the published analyses of iron, and it was supposed that its most 
abundant sources were rutile, anatasse, iserine, ilmenite, and some other 
minerals. In two analyses of Norwegian ore, Mr. Riley found 36‘88 and 
40-80 per cent, of titanic acid present. In Belfast iron ore dried at 280° 
Fahr. he found as much as three per cent of this mineral. He believes 
that titanium exercises some beneficial influence in the manufacture 
of iron and steel, and that in this respect it is analogous to manganese, the 
exact nature of whose action is unknown. He supposes that titanium, 
from its affinity for carbon and nitrogen, acts as a carrier of cyanogen 
to the steel. 
Glucinum and its Compounds. — Perhaps the most exhaustive memoir that 
has appeared for a considerable period of time, is that by Professor Joy, in 
the American Journal of Science and Art (xxxvi.). The history of the 
discovery of this mineral is first given, and then follows a list of all the 
minerals in which it has been found, together with the names of the 
chemists who recorded its discovery, and those of the journals in which 
these observations were published. Glucinum is found in the following 
minerals : — Alexandrite, alvite, aqua-marine, beryl, chrysoberyl, cymo- 
phane, Davidsonite, emerald, enclasse, gadolinite, goshenite, helvine, 
leucophane, melinophane, plienacite, smaragd, and tyrite. There are 
twelve different methods by which glucina may be separated. (1) By 
