Nov. 3, 



KNOWLEDGE 



375 



The sting produces in most cases a small white mark, ^vll^ch 

 soon disappears, and, if on the hand, the pain, which is ex- 

 cruciating, gradually extends from the aflected spot up the 

 ami, till it reaches the axilla, where it often Ijecomes very 

 intense. Its duration varies from half an hour to several 

 hours, and even when the pain has ceased, the slightest 

 touch to the aflected spot, or, above all, the application of 

 cold water, will renew the pain. 



In considering the stinging-plants of Queensland, we 

 need only, for our present pui-pose, deal with the natural 

 order Urlicetf, and of the seventeen genera of that order, 

 found in Australia, we are most concerned with the two — 

 Urtica and Laportea. Their relation to the sub-tribes and 

 tribes of the order is shown in the following table, which 

 I have constructed in accordance with the classitication 

 adopted by Bentham and Von Mueller. 



Trtica. Laportea. 



Of the genus Urtica there are two species in Queensland, 

 both herbaceous plants : — 



1. Urtica incim, found chiefly on the Fitzroy river, and 

 said by M. Thozet, of Rockhampton, to grow in great 

 profusion. 



2. Urtica Ure)is, a common weed in this country, and 

 found in the neighbourhood of dwellings in Queensland. 



In the genus Laportea we have, on the other hand, the 

 three great stinging-trees to which I have referred. They 

 are : — 



1. Laportea giffus, a large tree, often attaining a height 

 of 1 00 ft or more ; but I have not myself seen any speci- 

 mens over 80 ft The wood is soft, tibrous, and juicy, and 

 the bark smooth and ash-coloured. TJie base of the tree 

 is supported by prominent angles or buttresses. The leaves 

 are from 1 ft to 1 ft. 6 in. long, and nearly as broad, 

 smooth above and sprinkled with a few stinging hairs, but 

 more or less covered with short, soft hairs underneath. It 

 is found chiefly in South Queensland. The sting is severe, 

 but, as far as my experience goes, not so bad as that of 

 L. moroifleg. 



2. Laportea photiuiphi/lla. — A tine tree, from GO to 70 

 feet in height, with a straight stem. The wood is soft, and 

 the leaves are almost elliptical in shape, nearly smooth, 

 and sprinkled with a few stinging hairs. It is found in 

 the Moreton Bay district, and also in North Queensland. 

 M. Thozet mentions having found it on the Fitzroy River. 



3. Lajiorica moroiiUs. — A small tree, with most virulent 

 stinging hairs. The lea\es, which are about 9 inches long, 

 are covered with short soft hairs on both sides. The fruit, 

 which I have only twice seen, is of a beautiful purple 

 colour, succulent, and densely clustered. This tree is 

 found chiefly in the Kennedy district in North Queensland. 

 Mr. Fitzalan, of Bowen, mentions that it is common about 

 Port Denison and Edgecumbe Bay. 



These three stinging - trees, which Bentham and Von 

 Mueller place in the genus Laportea, are by many botanists 

 included under Urtica. 



Of all the stinging-plants of Queensland the virulence 

 of which I have been so unfortunate as to ascertain prac- 

 tically, Lajiortea moroideg surpasses the others, both in the 



severity of the pain produced at the time and in the dura- 

 tion of its eflects. 



I would refer those who wish for further information on 

 this subject to Bentham's " Flora Australiensis," Vol. VI. 

 Ernest Bl.\ck. 



A FEW HINTS ABOUT THE RAIN- 

 BAND SPECTROSCOPE. 



SINCE writing to the I'imes on the subject of " The 

 Spectroscope and Weather Forecasting," I have had 

 so many letters and incjuiries from various parts for infor- 

 mation about the rain-band spectroscope and how to use 

 it, that I think a few concise rules and facts in regard to it 

 may prove acceptable to many readers of your widespread 

 and useful periodical. With your kind permission I will 

 briefly mention the following, viz. : — 



1. Adjust the focus and slit of the spectroscope so that 

 the lines in the spectrum may be of the clearest definition, 

 and whilst taking an observation, shade the eyes with the 

 hands, in order that all extraneous light may be excluded 

 as much as possible. 



2. Observe in a general way from ten to twenty degrees 

 from the horizon, and towards the quarter from which the 

 wind is blowing, but if the latter be not practicable, point 

 the instrument in a northerly, in preference to a southerly, 

 direction. 



3. If 80 per cent of the dark band be shown at the 

 zenith, heavy rain will certainly occur before long. 



4. During wet weather, the amount of rain-band may 

 be low ; this for the most part denotes fine weather to 

 follow. 



5. If the instrument be directed towards the point from 

 which the wind is blowing, and should the clouds be 

 passing in one and the same direction, and 20 per cent, or 

 less, of the rain-band be shown, no rain will follow for at 

 least six hours, in spite of any threatening appearance of 

 the sky. 



G. With a knowledge of the course and peculiar charac- 

 teristic of storms, which is not diflicult to acquire {ride 

 " Aids to the Study and Forecast of Weather," by W. 

 Clement Sey, M.A.), it is possible to foretell rain by the 

 help of the spectroscope with surprising accuracy. 



Observers will not be disappointed if the above sugges- 

 tions are carefully attended to. The principal difliculty 

 lies in determining the percentage of rain-band ; but this 

 is to be overcome by practice and experience, and they 

 will find that after a time the indications of tie spectro- 

 scope can be read at a glance of a few seconds in duration. 

 F. W. Cory, F.M.S. 



SATURN'S RINGS. 



rpUE volume of "Philosophical Transactions' from 

 JL which I forwarded you the extract given in Na 49, 

 p. 307, is in my possession, and is peculiarly interesting. 

 The title-page is as follows : — 



" Philosophical Transactions : giving some Acconipt of 

 the present Undertakings, Studies and Labours of the 

 Ingenious in many considerable parts of the World. ^■oI. 1. 

 for Anno 1CC5 and IGGG." These Transactions were not 

 issued by the Royal Society, but were edited by their 

 Secretary, llinry Oldenl)urg. The first number was issuetl 

 on Jloniiay, March G, 1GG|, and was followed by montlily 

 parts in April May, June, July. At the end of the July 

 number is this note : — 



" jlrfi'trdMnittit.— The reader is hereby advertised that by reason 

 of the present Contagion in London, which mny nnlmppily cause an 



