The :ry of C< yflr. 'Ufa fhn. 287 



of October, when the frolt becomes fharp : nor did I ever 

 fee them again before the laft week in May, or beginning of 

 June. From their being envelo[ed in balls of clay, without 

 any appearance of food, I conceive they fleep during the 

 winter, and remain for that term without fuftenance. As 

 foon as f convened this fpecimen to my houfe, I depefked 

 it, as it was, in a fmall chip-box, in feme cotton, waiting 

 with great anxiety for its waking; but that not taking place 

 at the feafon they generally appear, I kept it until I found it 

 begin to fmell : I then fluffed it, and preferved it in its torpid 

 pofition. I am led to believe its not recovering from that 

 ftate, arofe from the heat of my room during the time it was 

 in the box, a fire having been conftantly burning in the 

 flove, and which in all probability was top great for ref ira- 

 tion. I am led to this conception from my experience of 

 the fnow bird of that country, which always expires in a few 

 days (after being caught, although it feeds perfectly well) 

 if expofed to the heat of a room witli a fire or flove; but 

 being nourifhed with fnow, and kept in a cold room or paf- 

 fage, will live to the middle of fummer. 



The animal above defcribed belongs to Schreber's genus of 

 Dipus, and may be characterifed 



DlPUt. C A n a DENSIS pahnis tetrad tlfis, planus pentadadylis t 

 tan Ad annul at d undique fetosd, corpore longiore. 



Fig. I. Pi ite VIII, reprefents the Dipus Canadenfis. 



Fig. 2 (hows it in its torpid ltate. 



XI- On the Theory of the Structure of Cry/tals, by the Abbe HaUT. 



From Vol. XVII. of the Annalcs de Chimie. 



[Continued from P>ige 169.3 



4. Intermediate Decrements. 



J. HERE are certain cryftals in which the decrements on 

 the angles do not take place in lines parallel to the diagonals, 



but 



