SCIENTIFIC SUMMARY. 
459 
the reagents employed, and the substances they help to throw down and 
separate from an aqueous solution : — 1. Chlorhydric acid precipitates lead, 
mercury, and silver. — 2. Sulphuric acid precipitates lead, barium, strontium, 
and calcium. — 3. Baric hydrate sets free ammonia ; the filtrate is used for 
the detection of sodium and potassium. — 4. Zinc is added to the filtrate- 
from 2, the hydrogen ignited and tested for antimony and arsenic ; antimony, 
arsenic, tin, mercury, copper, cadmium, and bismuth are precipitated. — 5. 
Baric carbonate precipitates, from the filtrate of 4, iron, chromium, and 
aluminium. — 6. Ammonic carbonate, after removal of the baryta, precipi- 
tates, from the filtrate of 5, manganese and calcium ; the filtrate is tested for 
magnesium, cobalt, and nickel. — 7. Zinc is tested for in the original solution. 
GEOLOGY AND PALAEONTOLOGY. 
The Osteology of the Mesotherium forms the subject of a fine series of 
memoirs presented to the French Academy by M. Serres. In the first com- 
munication, he treats of the structure and relation of the several parts 
composing the vertebral column, and supplies tables in which are recorded 
the exact measurements of the various bones examined. The atlas axis, 
fifth dorsal, eighth lumbar, and fourth cocygeal vertebrae have been 
especially dwelt on by the author. M. Serre3 remarks that, in determining 
the true osteogenical relations of the parts of the skeleton, it is necessary to 
study the bones in their foetal state. This is, of course, impossible in the 
case of fossil skeletons. He suggests, therefore, that the palaeontologist 
should examine the state of solidification and the density of the different 
parts of the compound bones. This, he says, will give a clue to their 
developmental relations. This rule applied to the Mesotherium shows that 
in the development of its spinal column, the laminae, as in all mammalia, 
were the first to ossify ; the ossification of the centres took place subse- 
quently. — Yide Comptes Rendus, July and August. 
The Volcanic Disturbances at Santorin. — A letter published in a late number 
of L’lnstitut reports that the disturbances of the Santorin group of islands 
continue. New portions of the sea-bottom have been elevated, and some of 
them have appeared above water. The raised portions are within four or 
five metres of Micra-Kammeni. Formerly the channel was twenty-one 
inches deep, but it is now not more than three. The island of Aphroessa 
remains stationary, but Yattia is now divided into two islands. Around 
the newly-formed lands the sea is of a yellowish-green colour, and has 
a temperature varying, according to the locality, from 25° to 75° centigrade. 
M. Cigalla, who has studied the volcanic phenomena very carefully, thinks 
another great eruption will soon occur, and that a true volcanic crater will 
be formed at the top of the George island. 
The Magnetic Needle in the study of Volcanic Districts. — A theory of some 
novelty, and which appears to have been put to a practical test, has been 
started by M. Jansenn, who has been exploring the Santorin region. This 
eminent physicist alleges that the magnetic needle may be employed to detect 
disturbances which take place at such a depth that they are not recognisable 
