AND OBSfiRVATIONS ON LAC. 



99 



contrary, the rnoft ilriking analogy is evident, between the wax It greatly re- 

 of lac and the myrtle wax which is obtained from the Myrica^™ % esmyrte 

 cerifera. 



An account of the latter fubftance has been publilhed by 

 TDr. Boftock, of Liverpool, in Nicholfon's Journal, with 

 comparative Experiments and Obfervations on bees-wax, 

 fpermaceti, adipocire, and the cryftalline matter of biliary 

 calculi. * 



The properties of the myrtle wax, as defcribed in Dr. 

 Bollock's valuable paper, fo perfectly coincide with thofe 

 which I have obferved in the wax of lac, that I cannot but con- 

 sider them as almoft the fame fubftance; indeed I think they 

 may be regarded as absolutely identical, if fome allowance be 

 made for the flight modifications which have been produced by 

 the different mode of their formation. 



From the preceding experiments and analyfes wp find, that Component parta 

 the varieties of lac confift of the four fubftances which have ° ac * 

 been defcribed, namely, extractive colouring matter, refin, 

 gluten, and a peculiar kind of wax. Refin is the predominant 

 Jubilance ; but this, as well as the other ingredients, is liable, 

 in a certain degree, to variation in refpect to quantity. 



According to the analyfes which have been defcribed, one 

 hundred parts of each variety of lac yielded as follows: 



Slick Lac. 



Kefin - 



- 



63. 



Colouring extract - 



- 



10. 



Wax 



- 



6. 



Gluten - 



- 



5.50 



Extraneous fubftances 





6.50 

 9.60. 



Seed Lac. 







Re/in - - - 



- 



88.50 



Colouring extract - 



- 



2.50 



Wax - 



- 



4.50 



Gluten - 



- 



2. 



97.50. 



Nicholfon's Journal for March, 1S03, p. 129. 

 H2 



Shell 



