Dr. C. Murchison on the White Secretion o/Flata limbata. 357 



and with a dense tuft of white pectinated appendages adhering to. 

 the dorsal and lateral aspects of the posterior segments. These 

 appendages were about two -thirds of an inch in length, and in the 

 fresh state spread out in all directions from the tail, some of them 

 curving upwards and forwards towards the head. They were 

 extremely fragile, the slightest touch reducing them to a fine white 

 powder, with which the whole body of the insect was thickly 

 bestrewed. Distinct from these there were on each insect two 

 smaller tufts of straight white filaments, exhibiting under the 

 microscope the ordinary characters of the hairy appendages found 

 upon insects, with a tendency to split up at their distal extremities. 

 These insect-cases were evidently the remains of the pupal stage of 

 the more perfect insect which had sprung away. The author then 

 proceeded to show the identity of this insect with Plata limbata, 

 originally described and figured by Sir George Staunton in his 

 account of Lord Macartney's ' Embassy to China ' (vol. i. p. 353), 

 as the source of the Chinese Insect-wax, and afterwards by Mr. 

 Westwood in his edition of Donovan's 'Insects of China' (p. 40. 

 pi. 17), and in the ' Gardener's Chronicle' for July 1853. 



After considering the importance of the Chinese Insect -wax, in 

 an economical point of view, and enumerating the several uses, 

 medicinal and economical, to which it has been applied in this 

 country and in China, the author proceeded to mention the various 

 sources to which the substance had been attributed. He quoted the 

 statements of Sir G. Staunton and others already alluded to, which 

 referred it to the white secretion of the Plata limbata. He then 

 alluded to the detailed observations on the subject which have been 

 recorded by Capt. Hutton of the Bengal Service in the Asiatic 

 Society's Transactions (1843), in which that gentleman had endea- 

 voured to prove, that the substance formed by the Plata limbata 

 presented very different properties from those of the Chinese wax. 

 He showed, however, that Capt. Hutton had confounded the viscid 

 excretion of the insect with the white secretion originally described 

 by Sir George Staunton, and which in its properties is really almost 

 identical with the Chinese wax. 



He then observed, tiiat in the Reports of the Juries of the Great 

 Exhibition of 1851, the Chinese Insect- wax was said to be the 

 produce of the male Coccus ceriferus. This insect, however, had 

 been shown by Dr. James Anderson to yield the " white lac " of 

 Madras, a substance which presented verj' different chemical rela- 

 tions from those of the Chinese wax, being, as shown by Dr. Pear- 

 son, soluble in alcohol and aether, and of higher specific gravity than 

 water. 



The author then reviewed the elaborate paper on the subject of 

 the Insect-wax published in the ' Pharmaceutical Journal ' (April 

 1853) by Mr. D. Hanbury, in which that gentleman had endeavoured 

 to show that the substance was the production of a species of Coccus 

 hitherto undescribed. His conclusions were drawn from specimens 

 of the crude wax, as scraped from the tree, transmitted to him by 

 William Lockhart, Esq. of Shanghae, in which were a number of 



