SCIENTIFIC SUMMARY. 
427 
Tolume. This fills thirteen pages in double columns, and is an almost ex- 
haustive enumeration of the works and scattered papers which relate to this 
group of plants. 
Dibtrihution of Potassa and Soda in Plants. — In a recent number of the 
Comptes Rendus,” M. E. Peligothas endeavoured to determine whether a 
plant, watered during the entire period of its growth with water holding in 
solution common salt and nitrate of soda, absorbs a certain quantity of soda ; 
and whether it takes from the soil other elements from plants of the same 
species cultivated under identical circumstances, but watered, some with 
common water and others with potassic and magnesian solutious. The 
tabulated observations show that the common salt and the nitrate of soda 
have been totally left by the plants j none of the ashes contained soda. 
Nitrate of soda acts only in consequence of the acid it contains, which pro- 
bably combines by double decomposition with potassa or lime. 
Pith of the Balsam Fir. — According to Dr. Dawson’s researches, the pith 
of the balsam fir {^Ahies halsamed) has the same curious structure of pith 
that he years since found in Sternbergia, the pith of a Devonian conifer. 
It is well seen in young twigs one or two years old, and closely resembles 
that of Dadoxylon Materiariiim of the upper coal formation of Nova 
Scotia. The structure is in each case an “ organic partitioning of the pith 
by diaphragms of denser cells opposite the nodes.” 
Concealed Chlorophyll in Plants. — M. Prillieux (^‘ Comptes Rendus,” 
June 26th), discusses the structure of the bird’s-nest orchis (^Neottia nidus- 
avis'), which is generally considered a non-parasitic plant not containing 
chlorophyll. He observed that if a plant is placed in alcohol it turns green, 
and then imparts that colour to the alcohol. Under the microscope it is 
seen that the brown colour of the petals is due to small elongated brown 
bodies scattered without order through the cells and grouped round the 
nucleus in each cell. These bodies have the power of swelling, and are 
what he regards as proteinaceous analogues of crystals. The application of 
alkalies or acids, or even of heat, immediately turns them green, and any 
re-agent which dissolves chlorophyll itself in like manner becomes green. 
M. Prillieux (“ Academy,” August 1st) believes, however, that chloro- 
phyll does not exist as such in the living plant, the most careful experi- 
ments showing no disengagement of oxygen, but rather of carbonic acid ; 
the chlorophyll is probably rather a product of the action of the re-agents 
applied. The tissues contain abundance of starch, which they probably 
absorb in that state. 
CHEMISTRY. 
The direct Synthesis of Ammonia. — An interesting experimental manufac- 
ture of ammonia by mixing dry hydrogen and nitrogen, and sending the 
electric spark through them, has been recorded by Mr. W. E. Donkin, who 
has lately read a paper on the subject, which has appeared in abstract in the 
Proceedings of the Royal Society.” He says, that ‘‘ The action of induced 
