Ferdinand von Mueller

1

Letter not found. For the text given here, see 'Lerp', Inglewood advertiser, 2 April 1861, p. 3 (B61.04.01). For a summary, see 'A native sugar', Argus, 8 April 1861, p. 5.

Sir, —

Professional engagements during the greater of this month in the Australian Alp has been the cause of my tardiness in acknowledging the receipt of some saccharine substance forwarded from Inglewood for my inspection. The substance in question is the cup-like covering of a psyllideous insect, found on certain species of eucalyptus, especially the mallee eucalyptus (E. dumosa). An excellent account, by Thos. Dobson, Esq., on the origin and development of this substance will be found in the "Papers of the Royal Society of Van Dieman's Land," vol. I., 1853, p.p. 235-241, plate xviii.;

2

The date is incorrect; the reference is to Dobson (1851).

and this essay is accompanied by a reprint of the observations published by Dr Thos. Anderson, in the "Edinburgh New Philosophical Journal," July, 1849,

3

Anderson (1849), reprinted as Anderson (1851).

particularly throwing light on the chemical constitution of this substance.

As the papers above quoted are readily accessible for ampler information, it may suffice for the general reader to repeat the principle contents. The saccharine matter found this season so abundantly around Inglewood is called by the Aborigines of the Mallee Scrub "Loap" or "Lerp," and was brought to scientific notice from the vicinity of the Avoca, where specimens for home transmission were gathered by Robt. Cay, Esq. The little shell like cups, covered externally with curled hair, and resembling flakes of snow, originate from an insect — the psylla eucalyti — the larvae and pupa of which exude the sugary substance from the extremity and articulations of its body.

This substance, passes usually under the name of "manna," but has no claim to such an appellation, not containing the characteristic mannita, but resembling, in its sacharine contents grape sugar.

Dr Anderson's analysis establishes the following chemical constitution of the Lerp:—

From this investigation it is apparent that the Lerp is free from unwholesome ingredients. It is entirely different in form, although similar in chemical character, to the crumb-like spurious manna, which occasionally during the summer season may be copiously collected under the trees of eucalyptus viminalis, improperly called, sometimes wax, sometimes peppermint trees.

Although the Lerp can only be of benefit to cursory travellers, it possesses yet sufficient interest as to deserve a place amongst the natural productions of Victoria to be transmitted to the forthcoming International Exhibition.

4

International Exhibition, London, 1862.

I beg, therefore, to call on any of your readers inclined to support the labors of the Commission now engaged to promote a worthy representation of our natural and industrial resources, not to omit the Lerp amongst the more important articles to be transmitted for exhibition.

Melbourne Botanical and Zoological Gardens,

26th March, 1861.