226 
PRACTICAL THOUGHTS ON LIGHT, 
boiling. These acid liquors were then mixed and concentrated by boiling. The bitter 
acid concentrated liquor was then treated with carbonate of soda. The precipitate was 
collected, then mixed with distilled water, and sulphuric acid added carefully. A per¬ 
fectly neutral condition was obtained by adding carbonate of soda. The fluid was filtered 
hot, and the neutral bitter liquid was afterwards set aside to cool, in the hopes that 
crystals might be obtained. Crystallization did take place on glasses under the micro¬ 
scope. The crystals are long and needle-shaped, and were so abundant as to appear 
to the naked eye as a whitish spot on the glass. A thin film of crystals (sulphate of 
quinine ?) also formed in the surface of the fluid, and could easily be skimmed off. 
These, dissolved in water slightly acidulated with sulphuric acid, tasted very bitter. At 
this stage, however, the process was arrested, notwithstanding the removal of colouring 
matter by animal charcoal. The detection of crystals at all, with the means at our dis¬ 
posal, was unexpected. As it is, the undoubted presence of little needle-shaped crystals 
in a fluid obtained from the leaves of Cinchona is worthy of record. 
4. The cultivation of Cinchona in British Sikhim is certain to be commenced soon by 
private individuals. Five hundred plants have been procured by private individuals from 
Mr. Mclvor at Ootacamund, but they nearly all died on the route, one plant having 
reached Darjeeling alive. However, I have applications for more than fifteen lacs of 
plants, and I shall soon be able to supply a few. 
Return of Cinchona Plants in the Government Nursery at Darjeeling 
on the lbth June 1863. 
Names of Species. 
Number on the 1st 
April, 1863. 
Number of Plants 
on 15th June, 1863. 
C. succirubra . 
420 
1,024 
C. Calisaya. 
51 
53 
C. officinalis . 
125 
573 
C. micrantha . 
323 
695 
C. Pahudiana .. 
1,892 
2,275 
Total. 
2,811 
4,620 
From T. Anderson, Esq., M.D., Superintendent of the Botanic Gardens, Calcutta, to the 
Secretary to the Government of Bengal.—(No. 49, dated the 7th August, 1863.) 
With reference to my letter No. 13, dated 9th September, 1862, announcing the discovery 
of febrifuge properties in the leaves of Cinchona succirubra cultivated at Darjeeling, 
and to my Report, dated 25th July, 1863, and which I lately submitted as an Appendix 
to first Annual Report on the cultivation of the Cinchona at Darjeeling, I have the honour 
to inform you that I have to-day received intelligence from England of the discovery of 
quinine in small quantities in the leaves of Cinchona sent from this country. Quinine 
obtained from the leaves was exhibited by Mr. Howard at the meeting of the Linnean 
Society, London, on the 18th June. This discovery confirms my opinion that the crystals 
which Dr. Simpson and I obtained at Darjeeling on the 20th and 21st June, as detailed 
in my last Report already referred to, were those of sulphate of quinine. As this is a 
discovery of importance, increasing the value of the Cinchonas from the existence of 
quinine in the leaves, I have to suggest that this letter and the letter to your address, 
No. 13 of 9th September, 1862, and No. 36 of 8th May, 1863, may be published, along 
with the Annual Report, in the Supplement to the ‘Calcutta Gazette.’ 
PRACTICAL THOUGHTS OH LIGHT. 
Some time ago, while sitting at my desk, I observed that one of the show car¬ 
boys in the window had focussed the sunlight on my coat-sleeve, and was burning 
it. It is quite possible that many fires may have taken place in this way 
when no satisfactory reason could be given for their occurrence. It would be well, 
