PLYMOUTH INSTITUTION. 235 



colour is white, and its lustre brilliant. No attempt has been made 

 by him to combine two or more filaments into one by winding, nor, 

 of course, to form it into thread by throwing. 



The thread of the garden- spider is so much finer than that of the 

 silk worm, that the united strength of five of the former is, accord- 

 ing to Mr. Rolt, only equal to one of the latter ; and, as he has not 

 been able to devise any means of overcoming the pugnacious dispo- 

 sition of the animal (which is such, that to prevent his little labourers 

 from destroying each other, he is obliged to shut them up in sepa- 

 rate dens or cells) the subject cannot be considered as much, if at 

 all, advanced by his experiments beyond the point where M. 

 Reaumur left it.'' 



Having given a number of other instances of the extreme minute- 

 ness of which matter is susceptible, the lecturer went on to shew 

 that this division might be carried on ad infinitum, though philoso- 

 phers had themselves assumed a limit beyond which they forbid the 

 further division of matter; the last particles they have termed 

 ultimate atoms. 



The lecturer stated it as his opinion that the assumption of the 

 existence of atoms was perfectly gratuitous, and could neither be 

 borne out by experiment nor analogy. He considered it as impos- 

 ing a limit upon Nature, because our senses failed to follow her to 

 a sufficient extent ; and that the only benefit which appeared to 

 arise in the assumption of atoms is, they act the part of x 1/ z in 

 Algebra, viz. — by giving a determinate name to an undetermined 

 quantity. 



November 14. — Mr. Barnes' lecture on Criticism. 



The lecturer commenced his paper by alluding to a statement 

 which he made in his last lecture, viz., that under a common name 

 was comprehended criticism, both as a science and an art. It was 

 his design now to consider the art of Criticism, which is, the inven- 

 tion of rules for directing the mind in forming a correct judgment 

 of the works and actions of men. 



The actions and works of men, Trpa^eig kul it gay fxara, are all 

 referable to some art of which the agent is a professor; all actions 

 are referable to the art of morality, of which all men, as men, are 

 professors ; many actions are referable to the art of law, of which all 

 members of a civil society, as such, are professors, and many are 

 referable to other particular arts, such as brick making, architecture, 

 government, statuary, painting, poetry, &c. There is one art, viz., 

 that of government, which has caused the invention of an art of cri- 

 ticism as subsidiary to itself, confined to that class only of actions 



