and Magazine of the Ceylon Agricultural Society. 



365 



Since 1 had observed frequently bacilli on the 

 rolled tea leaves undergoing the fermenting pro- 

 cess, I was led to suppose that some relations 

 between these bacilli and chemical changes in 

 the tea leaf might exist. Hence I tried to kill 

 the ordinary microbes adhering to the leaves 

 and to infect the leaves with bacilli taken from 

 fermenting leaves. 



Fresh tea leaves were left in either for 4 

 hours, roiled and dried as usual. The green 

 colour of these leaves not only gradually changed 

 to brownish but also the characteristic aroma 

 of black tea was observed after 10 hours, in 

 spite of the odour of adhering traces of ether. 



This experiment shows that the aroma is not 

 caused by any micro-organisms. The same result 

 was obtained when the ether was substituted by 

 alcohol and chloroform. A.lso powerful antisep- 

 ticsas cresol, mercuric chloride were tried. Fresh 

 tea leaves were soaked in a 4 percent cresol solu- 

 tion for 24 hours washed once with distilled 

 water, dried in the sun and then rolled and kept 

 compactly in a flask. The tea leaves changed 

 gradually in colour to brownish black and after 

 15 hours produced a distinct aroma, modified 

 however by the odour of traces of cresol remai- 

 ning. Fresh tea leaves were left in a 1 per cent 

 HgOl(a) solution for 20 hours, whereby the leaves 

 assumed a pale appearance, and washed with 

 distilled water. When kept in a flask, the char- 

 acteristic aroma of black tea was also here ob- 

 served after some time, but the blackening of 

 the leaves was here not observed. When the 

 so-called fermentation process is allowed to 

 go on for too long a time before drying or 

 firing, the normal aroma produced gradually 

 disappears and a sour smell developes. Finally 

 white mould appears on the leaves. However, 

 if the leaf is treated with antiseptics as 

 above-mentioned, the sour smell is not ob- 

 served. These tests render it very probable 

 that the development of aroma is due to the 

 action of certain enzymes originally present 

 in the leaves which produce the specific volatile 

 oil of tea from certain compounds. This is in 

 analogy to the flavour of tobacco which is also 

 pcoduced by the action of enzymes (oxidases). 



I have further observed that after treating 

 tea leaves with cyanogen gas for 5 hours the 

 aroma fails to appear. When tea leaves are 

 repeatedly treated with ether or alcohol, the 

 aroma fails to develop which shows that those 

 substances which yield the aroma have been 

 extracted by ether and alcohol, which agrees 

 with observations of Kozai(&.) Since Kozai, 

 Bamber and other authors observed that black 

 tea cannot be manufactured from steamed 

 tea leaves, I have tried the influence of var- 

 ious lower temperature. The tea leaves were 

 kept at these temperatures for an hour and after 

 having gone through the usual process the 

 results were as follows : — 



40o C 

 60 „ 

 60 „ 

 65 „ 

 75 „ 

 100 „ 



good aroma 

 do 



only a very weak aroma 



no aroma, only a raw grassy smell 



do do 



do do 



This result supports my opinion, that the pro- 

 duction of aroma is caused by a certain enzyme. 

 As to oxidising enzymes their presence can 

 easily be demonstrated. When tea leaves are 

 treated with strong alcohol until tho tannin is 

 entirely removed, and then treated with distilled 

 water, the aqueous extract thus obtained be- 

 haves as follows : — 



Guaiac tincture. 



40 (aroma) blue 



50 ( do ) do 



60 (very weak) do 



65 (no aroma) do 



75 ( do ) no coloration 



100 ( do ) do 



Guaiac plus H20Z 

 deep blue 

 do 

 do 

 do 



no coloration 

 do 



Since the leaves kept at 65° devoloped no aroma 

 but gave still the reactions for oxidase, and 

 peroxidase, it appears that other enzymes than 

 these are concerned in the production of aroma. 



Post Scbiptum. 



As Mr Katayama having had to break off his 

 studies on account of his departure for India 

 and Europe, Prof, Sawamura made a further 

 experiment upon which he reports as follows : — 



" I extracted 156 g of fresh tea leaves with 900 

 0. c. of absolute alcohol and 147 g with 1 litre 

 of 20 per cent alcohol. The former extract was 

 evaporated to dryness and the residue dissolved 

 in water (A). The latter extract was precipitated 

 with t>ther-alcohol (B). By adding the preci- 

 pitate B containing the enzymes to the solution 

 (A), an agreeable aroma characteristic for the 

 prepared tea was-produced. ,; 



This result is a further confirmation of the 

 view, that the tea aroma is caused by the original 

 enzymes of the leaves. But the true nature of 

 the enzymatic process requires further study. 

 The most probable supposition is, however, that 

 a peculiar enzyme splits a certain glycoside 

 present in small quantities and that one consti- 

 tuent thus liberated yields by taking up oxygen 

 the aroma of tea. Y. Kozai. 



— Bulletin of the Imperial Central Agricultural 

 Experiment Station, Japan, Vol. I, No. 2, 

 Oct. 1907. 



(a.) On tea, a publication from India. (0.) 

 Bulletin College of Agriculture, Tokyo Imp. 

 Unvi, Vol. I., No. 7. 



A NEW COTTON FROM THE SOLO- 

 MON ISLANDS, 



" MAMARA ": MORE PROLIFIC THAN 

 CARAVONICA. 



We have this week received from Messrs. 

 Sturmfels, Limited, wool and produce broker, 

 of Brisbane, a sample of a new cotton grown in 

 the Solomon Islands, which promises to be a 

 rivai of Caravonica in its prolific yields and ease 

 of cultivation. We have examined the sample 

 in question and find it is, as reported, a fines 

 white silky cotton, and one which certainly 

 ought to command the high price at which it is 

 valued. It is a pity, however, that the cotton 

 has not been sent to us just as it was gathered — 

 in the boll— so that the quantity of lint, per boll 

 and in comparison with the bulk of seed, might 

 be judged. The staple is a good average one 

 — about an inch in length. This " Mamara " 

 Cotton will be found duly advertised in the 

 September issue of the Tropical Agriculturist. 



