481 Intelligence and Miscellaneous Articles. 



the other parts of the square remain unchanged, and it continues 

 suspended. 



(5) If the charge be increased to 2*5 grins, for instance, all other 

 conditions remaining the same, the square is smashed into a number 

 of pieces which fall almost vertically. To ascertain the shape of 

 the debris, a sheet of paper may be fastened on one or both of the 

 faces of the glass : the principal phenomena are unchanged ; and it 

 is seen that with small velocities the hole produced in the paper is 

 well denned and round without projections on the side struck, while 

 with greater velocities the edges of the paper are strongly jagged on 

 the two sides. 



These experiments were made with squares of all sizes, varying in 

 thickness between 1 and 5 millims., and either suspended, fixed, or 

 cemented. They may even be inclined at an angle of 45° to the 

 trajectory without materially altering the phenomena. 



Comparing these experiments with those which prove the transpor- 

 tation of the air, we must conclude that the air which precedes the 

 ball commences the action ; and we may perhaps be able to prove 

 that the square is perforated in certain cases before being actually 

 reached by the projectile. However this may be, it seems to me 

 that we have generalized too widely in the application of the cele- 

 brated experiment of the Abbe Camus*. 



We frequently confound, in the question of the impact of solid 

 bodies considered from this point of view, the effect of rupture, or the 

 molecular motion communicated to the body struck, with the effects 

 of the translation of matter in the direction of the projectile striking 

 the body at rest, and the motion of translation of the whole of this 

 body. 



I am obliged to my friend Major Caron for having enabled me to 

 show my experiments to several artillery officers and other French 

 scientific men, after having arranged the apparatus in the chemical 

 laboratory under the direction of the artillery committee. — Comptes 

 Rendus, September 30, 1867. 



ON PHOSPHORESCENT LIGHT. BY DPv. KINDT IN BREMEN. 



If a piece of chlorophane, which, heated in a tube, gives a green 

 light visible even by daylight, be viewed in the dark through a spec- 

 trum-apparatus, homogeneous green only is seen. Phosphorite of 

 Estremadura (which gives a yellowish light) shows green, yellow, 

 and red. A green fluorspar from the Breisgau shows, on the contrary, 

 two dark lines in the green, one of which is near the orange-red. Two 

 other, bright-green fluorspars, of unknown localities, present the same 

 phenomenon. The dark lines are as powerful as in solutions of didy- 

 mium. — Poggendorff's Annalen, No. 5, 1867. 



* A musket-ball piercing a piece of wood of considerable thickness with- 

 out communicating to it any appreciable velocity (Memoir es de VAca- 

 demie des Sciences y 1738). 



