236 Notices respecting New Books. 
una forma binaria dell' ottavo ordine," and " II risultante di due 
forme binarie l'una cubica e l'altra biquadratica:" two notes by F. 
Brioschi. " Ueber potentiale w-facher Mannigfaltigkeiten," L. 
Kronecker : gives a very simple expression for the potential of an 
ellipsoid, of «-piicity, which is not referred to its axes. " Sopra la 
propagazioue del Calore," E. Betti : treats of the movement of heat 
in an indefinite isotropic medium, all whose points are of zero tem- 
perature with the exception of points contained in a certain deter- 
minate space. " Ueber quadratische Kugelcomplexe und confocale 
Cyeliden," T. Reye : extends the notion of a normal to spherical 
linear complexes, and obtains a system of orthogonal and homo- 
focal cyclides. Alcuni teoremi sulle funzioni di una variabile 
complessa," U. Dini : discusses theorems due to Weierstrass, Betti, 
and Mittag-Leffler. " Einige Bemerkungen iiber die Lame'schen 
Eunktionen," L. Schlafli; "Ueber die Abspiegelung der Sonnen- 
fleckenperiode in den zu Bom beobachteten magnetischen Varia- 
tionen," R. Wolf ; " Ueber die dreifachen Secanten einer alge- 
braischen Baumcurve," C. E. Geiser : this last discusses a problem 
in numerical geometry. " Una formola fondamentale concernente 
i discriminanti delle Equazioni differenziali e delle loro primitive 
complete," E. Casorati : finds a relation between the discriminants 
of a differential equation and of its primitive. " Sulle curve gobbe 
razionali del 5° ordine," E. Bertini : this is an investigation of some 
properties of quintics (skew, rational and without double points) 
which the author ranges under two species. " Sui moment! obliqui 
di un Sistema di Punti e sull' 'imaginares Bild ' di Hesse," G. Jung : 
we must refer our readers to the paper for the definition of oblique 
moments &c. " Sulla teoria degli assi di rotazione," E. Beltrami : 
an. excellent paper, which fittingly finds a place here, as it follows 
on the lines of Chelini's " Elementi di meccanica razionale " (and 
of Prof. Turazzo's " II moto dei Sistemi rigidi "). " Intorno ad un 
Testamento inedito di Nicolo Tartaglia," an autographic reproduc- 
tion which is presented with all Signor Boncompagni's well-known 
wealth of bibliographical illustration. An interesting fact which 
comes out is the settlement of the date of Tartaglia's death (" a 
serte ore della notte dal lunedi 13 al martedi 14 dicembre del 
1557 ") against the erroneous dates given by Libri, Poggendorff, 
Hankel, and others. " Sopra una certa superficie di quart' ordine," 
L. Cremona : treats of the surface generated by projective pencils 
(fasci) [S,-|-XS 2 =0, S 3 + XS 4 =0] of surfaces of the second degree, 
on the supposition that the surfaces (S = 0) touch at the same 
point. 
EOBEET TlTCKEB, M.A. 
