SCIENTIFIC SUMMARY. 
311 
colourless ; niobium, blue ; and ilmenium, brown. Hermann refers to other 
reactions which serve to identify it. He has determined the atomic weight 
of neptunium by an analysis of the neptunium-potassium fluoride (4 K FI + 
Np 2 Fl 7 + 2 H 2 0) and finds it to be 118-2. The combining numbers of the 
metals of this group form the following series : — 
Tantalum 
176* 
Neptunium 
118-2 
Niobium . 
114-2 
Ilmenium 
104-6 
The metal itself has not yet been prepared, the author having at present 
only forty grains of the hydrate of the metallic acid for investigation. As- 
suming, however, that neptunic acid (Np 4 0 7 ), obtained by igniting the 
hydrate, is similarly constituted to the corresponding oxide of niobium, he 
calculates its specific gravity and atomic volume. He finds the density of 
neptunium to be 6*55, and the atomic volumes of the metals of this group 
form the following series : — 
Tantalum 
. = 16-5 
Niobium 
16*5 + (1 x 0-5) 
. = 17-0 
Ilmenium 
16-5 + (2 x 0-5) 
. = 17-5 
Neptunium 
16*5 + (3 x 0-5) 
. = 18-0 
While the precipitate formed on the addition of soda to the fluoride of the 
new metal is, as has been stated, insoluble, neptunic acid when fused with 
soda and treated with boiling water dissolves in that menstruum, and pris- 
matic crystals separate from the liquid as it cools. Tantalum, on the other 
hand, when similarly treated, deposits crystals which have the form of hexa- 
gonal plates . — Journal fur praktische Chemie , 1877, xv., 105. 
Trimethylamine . — Vincent directs attention to the value of this compound 
in analysis. After describing the mode of preparation he refers to some of 
its reactions which differ in many important respects from those of ammonia. 
With trimethylamine the salts of aluminium form white gelatinous precipi- 
tates which dissolve in an excess of the reagent. The salts of cobalt, nickel, 
copper and zinc form precipitates which do not disappear on the addition 
of a large excess of trimethylamine. The salt of silver forms a dull grey- 
coloured precipitate which dissolves in a large excess of the compound 
ammonia ; the chloride of this metal, on the other hand, appears to be quite 
insoluble in trimethylamine. A substance which exhibits reactions so 
strongly contrasted with those of ammonia cannot fail to be of great use in 
special branches of practical chemistry. — Bull. Soc. Chimie , Paris., xxvii., 
194. 
The Chemical Composition of the Flesh of the Halibut . — The halibut 
(Hippoglossus americanus, Gill), which abounds in the waters of the Atlantic, 
as far north as Newfoundland and as far south at Cape Hatteras, is highly 
valued as food in the United States. The flesh is of a fine white colour, is 
delicate and tender, and resembles that of the whiting ( Merlangus vulgaris). 
The fresh flesh of the halibut has been analysed by Chittenden, and he 
gives in his paper the results of his examination side by side with those of 
