0*1 THE GRUB OF THE COCK-CHAFER. 73 



which might aker them if they were left in it too long. In 

 lhis ea<fe, the lime-water with which the leather would charge 

 itfelf, would determine a more fpeedy precipitation of the 

 tanin, and its union with the lime as well as with the gelatine 

 contained in the leather. I believe alfo that by this means 

 the leather would acquire more weight, a quality in requeil 

 amongfi the tanners, and perhaps it would become lefs per- 

 meable to water. » 



Thefe are only conjectures which I advance, as they appear 

 to me to be dictated by the theory of the art of tanning. In 

 this inftance probably, as in many others, the practice will not 

 correfpond with the theory. I recommended the trial to ma- 

 nufacturers, and fiiall make it myfelf when a favourable op- 

 portunity offers. Annales de Chimie, No. 123. 



V. 



On the Dejlruclion of the Grub of the Cock-cluifer. By Edward 

 Jones, Efq. ofWepre-Hall, in Flint/hire*. 



JL HE grubs of the cock-chafers (or brown beetles) are white, Defcription of 

 about an inch in length, and of the thicknefs of a turkey's f^^ f f thc 

 quill. When difturbed they contract their length, and their 

 bodies dilating, appear like lumps of white fat f, fomewhat 

 oval. 



They inhabit fandy and light loamy foils, lie from about Sanation. 

 two to fix inches deep, and may be found in fpring, by paring 

 off the fods. 



This place was much infefted by brown beetles ; but about 

 twelve years ago, fome labourers removing a bank of earth, 

 expofed a bed of grubs, feveral paces in length. Many of 

 them were fcattered among the fallen foil; and one of the 

 men propofed to ft rip the furface of the bank, which being 

 done, the grubs were feen lying in irriguous channels, as if 

 the parent infects had dropped the eggs moving in various 

 directions. 



# Extra&ed from a letter to the Society for the Encouragemefit 

 cf Arts. Tranf. for 1801. 



f Hence the Britifh name " Earth-Lard." 



The 





