36 * 
ADDENDA ET CORRIGENDA. 
the loose cellular structure of the bark produced by artificial means. To these must be added a circumstance that I have long 
observed, more especially among the varieties of G. officinalis, that trees which are from their position fully exposed to sunshine 
have a proportionally larger amount of Chinchonidine than those grown in shade. 
“ Mr. Howard, to whom I communicated this observation, informed me that it quite agrees with his experience. The yield of 
Quinine in the Ceylon Crown barks was greater in those grown in shade than in those fully exposed. Dr. De Vrij has observed 
the same peculiarity. 
“ The same fact harmonizes with the opinion prevailing in South America, that the bark of Uritusinga varies in quality 
according to the aspect of its situation with respect to the sun. If it be the heat of the sunshine that produces these effects, it will 
be seen that exposed bark would in many respects be under the same conditions as that grown in a warmer climate. The sunshine, 
which is powerless to warm the dry and diathermanous air of the Neilgherries, falling on the bark, at once raises its temperature. 
“ These observations derive additional force from the consideration, that it is in this respect of effective heat-giving sunshine 
that the climate of the mountain ranges of South India differs from that of the Chinchona regions of South America. With the 
same annual mean atmospheric temperature, the climate of the Neilgherries differs from that of the bark regions, in having six 
months of unclouded sunshine wdien the singular dryness of the atmosphere robs the rays of none of their heating power. The 
bark countries of the Andes are, unlike ours, situated in a region of perpetual trade-winds, which, as our monsoons, bring their 
abundant rains and fogs during the greater part of the year to interrupt the sunshine. The travels of Markham, Karsten, Spruce, 
Boussingault, and many others bear full testimony to this.” 
The elevation of 6000 to 7000 feet appears to be most favourable to the yield of Quinine in the G. succirubra ; above the latter 
height it diminishes. 
“ The fifth year of the life of the Red Bark trees is marked by a great increase in the number of the liber fibres of the bark, 
by which that portion becomes thoroughly developed. There appear to be some grounds for the conclusion that this development 
is not favourable to the yield of Quinine.” 
“ Frequent analyses made of the Red Barks during the last eighteen months have clearly shown that the yield of alkaloids 
varies according to the season of the year. The ratio that the amount of Quinine bears to the other alkaloids appears also to vary. 
Periodic analyses were begun fourteen months since, for the purpose of ascertaining the times of maximum and minimum yield, 
but at least a year more must elapse before I obtain sufficient data to decide this important subject. I may, however, state that 
the point of maximum yield falls within the period comprised between the beginning of February and the end of May.” 
I have remarked on the great variability which I have found in the products of the G. succirubra from South America, which 
may partly depend on the above cause. If I were forming a plantation, I should certainly not depend on this species as my main- 
stay. 
2. Mr. Broughton agrees with me in a favourable estimate of the Crown Barks, from which, however, must be deducted the 
disadvantage of a slower growth, and a consequent — perhaps one-third — less formation of bark than in the G. succirubra. The 
largest yield of Quinine in these barks occurred at the height of 8000 feet. 
“ The trees planted at the lowest slopes of the latter, yield barks which are also inferior in other respects, since they contain 
resinous and colouring matters which increase the labour of purifying the alkaloids. The cortical fibres are also more numerous in 
the low-cjrown Crown Barks. I have also detected Quinidine in these barks. The Quinine is in great part replaced by Cincho- 
nidine, exactly as in low-grown Red Barks.” 
“I have already expressed my conviction of the great value of our Crown Barks. Farther investigation has given no reason 
to alter that opinion. The Quinine which they contain yields a pure white crystalline sulphate with ease. Many specimens I have 
met with have been actually free from “ uncrystallizable Quinine.” Hence the Quinine is frequently so pure as to yield its theo- 
retical amount of crystallized sulphate. I have met with specimens of Crown Bark which yield upwards of five per cent, of purified 
alkaloid. 
“ Mr. Howard (whose correspondence and assistance have been of great service to my work) has informed me that he has 
satisfactorily identified a sub-variety of our Chinchona officinalis with that which yielded the bark known as Amarilla del Rey. 
This is a sort which has long enjoyed a high reputation among Pharmaceutists and Quinine manufacturers, and its possession is a 
very fortunate circumstance. It appears very easy to work, and yields Quinine readily, crystallizable as sulphate. In actual 
amount, however, it does not appear to differ essentially from its companion sub -varieties. 
“ Among the Crown Barks which were grown from seeds brought by Mr. Cross, are a few scattered trees, which present a 
marked difference from the rest of their companions. The leaves are of a narrow lanceolate shape. My attention being directed 
to the study of those varieties whose numerical importance claimed the earliest observation, it was not till recently that I made an 
analysis of this variety. Surprised by the result, I took the precaution of making an analysis of the adjoining trees of Chinchona 
officinalis, in order to eliminate the possible influence of peculiar conditions of soil, site, etc. 
“ The percentages of the respective alkaloids stand thus : — 
Bark of 
Bark of 
Lanceolate species. 
adjoining trees. 
Total alkaloids ....... 
8-0 
4-48 
Quinine ........ 
7-15 
2-06 
Chinchonidine and Chinchonine .... 
0-85 
2*42 
Sulphate of Quinine obtained crystallized 
7-37 
U n deter mine d . 
Do. Chinchonidine obtained crystallized . 
0T5 
Do. 
