WITHDRAWN FROM THE ACTION OF GRAVITY. 657 



cidity; and, after the demonstration given in § 57, this least 

 value will be at least equal to the limit of stability. Now as all 

 liquids are more or less viscid, it follows that, even on the hypo- 

 thesis of the annihilation of all external resistance, the proportion 

 in question will always exceed the limit of stability ; and since this 

 is more than 3, this proportion will a fortiori be always more 

 than 3. 



It is conceivable that the least value considered above, i. e. 

 that which the proportion would have in the case of complete 

 absence of resistance both internal as well as external, would be 

 equal to the limit of stability itself, or would very slightly 

 exceed it. In fact, on the one hand, the proportion approximates 

 to this limit as the resistances diminish, and on the other hand, 

 if it exceeds it, the transformation becomes possible (§ 57) ; 

 hence we see no reason why it should differ sensibly from it if 

 the resistances were absolutely null. The results of our experi- 

 ments, moreover, tend to confirm this view. First, since the 

 proportion belonging to our cylinder of mercury descends from 

 10*29 to 6*35, passing from that case in which the cylinder 

 touches the glass at two lines to that where it touches it at a 

 single one only (§ 58), it is clear that if this latter contact itself 

 could be suppressed, which would leave the influence of the 

 viscidity alone remaining, the proportion would become much 

 less than 6'35 ; and as, on the other hand, it must exceed 3, 

 we might admit that it would at least lie between the latter 

 number and 4, so that it would closely approximate the limit of 

 stability. If, then, it were possible to exclude the viscidity also, 

 the new decrease which the proportion would then experience, 

 would very probably bring the latter to the very limit in ques- 

 tion, or at least to a value differing but exceedingly little from it. 

 Thus, on the one hand, the least value of the proportion, that 

 corresponding to the complete absence of resistances, would not 

 differ, or scarcely so, from the limit of stability ; and on the other 

 hand, under the influence of viscidity alone, the proportion 

 appertaining to the mercury would be but little removed from 

 this least value. Hence it is evident that the influence of the 

 viscidity of mercury is small, which is moreover explained by the 

 well known feebleness of this same viscidity. 



We can now understand in the case of other but very slightly 

 viscid liquids, such as water, alcohol, &c., where the viscidity is 

 not able to form more than a minimum resistance, that this 

 viscidity, notwithstanding the differences in the intensities of the 



