96 



The Supplement to the Tropical Agriculturist 



sulphuric acid and then saturated with ammo- 

 nium sulphate and kept cold. The fluid was 

 then filtered and the filtrate kept for the ex- 

 traction with ethyl acetate of any excess of 

 tannin that might be present, or of caffeine by 

 means of chloroform. (It may be noted that 

 a very rapid method of ascertaining vvhether 

 tea infusion contains an excess of tannin 

 consists in saturating the infusion with 



ammonium sulphate and filtering. The 

 filtrate will contain any tannin present 

 in excess of caffeine tannate which 

 can be extracted by shaking with ethyl acetate 



separately and evaporating to dryness). The pre- 

 cipitate in the filter was allowed to dry as much 

 as possible in a current of air. The filter and its 

 contents were then exhausted with a mixture 

 containing 1 part of alcohol and two parts of 

 benzene. The extracts wore adHed together and 

 made up to a definite volume (100 c.c. ). A known 

 measure of this (25 c.c.) was evaporated upon a 

 weighed amount of lead oxide (approximately 3 

 grammes), keeping the mixture thoroughly stir- 

 red. The dry mass was then made into a paste 

 with water and extracted several times with 

 chloroform. The chloroform, evaporated care- 

 fully to dryness, gives the caffeine in the caf- 

 feine tannate. The lead residue was then care- 

 fully dried at 120 0. and weighed to constant 

 weight. The increase in weight gives the tannin 

 extracted by the lead oxide. Another portion of 

 the benzene-alcohol solution (25 c e. ) isevaporatod 

 to dryness to give the total caffeine tannate. 

 The Estimation of Total Tannin. —We found 

 that good and consistent results weio obtained 

 by taking 20 c.c. of the fresh infusion, 

 adding slight excess <>f bicarbonate of soda 

 and running in N/10 iodine solution to 

 which were added 400 c.c. of just boiling 

 water, the infusion being poured off after five 

 minutes. The qualities of the teas from the 

 merchants point of view are indicated by 



ANALY8E8 OF INFUSIONS OF VaKIOUS TEAS. 



Description. s. d. 



Indian .. 8-54 6'41 213 6-90 2'56 0M3 39 7j 



do .. 8-88 6'66 2-22 6'88 2'22 — — 8 



do ... H1-S2 7-74 2-58 7"39 2'88 0'30 — 8} 



do .. 11-48 8 61 2-87 841 352 0-65 — 84 



do .. I.C28 9-95 3-32 9 24 370 0'38 — Hi 



do .. 9-60 7 - 20 2-40 8-73 3 - 2u 0'80 1'53 UJ 



do .. 12-50 9-40 3-10 9-50 4'UO 0'90 O'lO 1"10/. 



do .. 13-36 1T02 3-34 10-92 4'32 98 0'90.1 L 1<| 



Ceylon 8 - 8S 6'66 2 22 6-30 2'80 0-58 - s£ 



do ... 9'12 6-84 2.28 7'14 3'04 076 3'30 iOJ 



do .. 10-4» 7-80 2V0 9.82 2Wi 0-38 2'02 1,)* 



do .. 1176 8>2 m 8-82 2". 6 002 — 101 



do .. 13-28 9 96 332 966 4'00 0*8 — 1" 1 



do .. l2 - 00 9-00 3-00 8 40 3-60 60 - 1" 4 



Cbina .. 6-36 4*02 1-34 3 02 1-92 £8 — 6£ 



do ... 6-60 4'20 1-40 4-87 272 V32 0-o7 8 



do .. 7-60 5-70 1-90 5-04 2-72 0'82 — 9| 



do ... 6-3! 474 l'?8 396 272 1-14 - 1" 1 



do ... 6-48 4-86 1-62 4-60 2"8-) M8 - 1V6 



until some petroleum either shaken after each 

 addition with the mixture showed a slight 

 excess or iodine present by the well-known 

 violet colour. The factor for tannin was each 

 c.c. of N/10 iodine used multiplied by 0*0021. 



Estimation of the Total Caffeine.— This was 

 estimated by first slightly acidulating the in- 

 fusion with dilute sulphuric acid, then boiling 

 with an excess of lead oxide. After half-an-hour 

 or so a clear pale yellow fluid resulted which 

 filters perfectly, and can then be several times 

 extracted with chloroform, which on evapora- 

 tion yields caffeine,— Lancet, 



SOIL FERTILITY. 



Two schools of agricultural chemists are now 

 in existence. Those who take the historic view 

 of Davy, Liebig and others that the lack of 

 fertility of a soil is due to its lack of substances 

 needed by the plant, which substances must be 

 added as fertilisers, and the school led by Whit- 

 ney and Cameron, who insist that it is the soil 

 solution that must be examined. They have 

 found in the soil substance like licoline, car- 

 boxylic acid and dihydroxystearic acid which 

 act as poisons and furnish the logical reason for 

 the rotation of crops. 



A book of Mr Cameron's gives an intelligently 

 stated resume of the views of this latter school 

 of agricultural chemists. We seem thus far to 

 have known as little concerning plant life as 

 concerning animal life. We know that we in- 

 hale and exhale air for a given purpose and that 

 fishes have a satisfactory arrangement for the 

 oxidization of their blood, but of these physio- 

 logical phenomena incident to plant life we have 

 known but little. It would now seem that 

 plants from a Darwinian point of view, are our 

 first cousins or perhaps older cousins as plant 

 life probably appeared earlier in the history of 

 this planet than did animal life, if we can draw 

 the line of distinction between the two. Aquatic 

 plants probably get their oxygen out of the 

 oxygen of water with a mechanism equivalent to 

 that of the fishes. Dry land plants get their 

 oxygen out of the air, which must permeate the 

 soil and there enter into this soil solution that 

 goes to build up plants. — Louisiana Planter, 

 Doc. 2. 



CEYLON GOVERNMENT AGRICUL< 

 TURAL SCHOLARSHIPS. 



Tonight's Gazette contain a notification re 

 above. As a first step it is proposed to grant 

 four scholarships tenable for a period of three 

 years for a course of training at the Agricul- 

 tural College at Poena. The scholarships w?H 

 entitle the holders to the following allowances 

 during the three years of their course of train- 

 ing : — A subsistence allowance of Rs. 50 per 

 mensem, and an outfit and travelling allowance 

 at the rate of Us. 300 per annum paid 

 half-yearly. The candidates will be pro- 

 vided with quarters, but they will have to 

 provide their own boarding. Fees for tuition, 

 cost of instruments, &c, and rent of quar- 

 ters will be paid by Government. The scho- 

 larships will be granted by nomination by 

 the Governor in Executive Council to selected 

 candidates who were over 19 and less than 24 

 years of age on Jan. 1, 1912. Applications for H 

 E the Governor's nomination must be submitted 

 to the Hon. the Colonial Secretary not later 

 than March 1, 1912. Each candidate must send 

 in with his application two certificates of charac- 

 ter, one of which must be from the Principal 

 of the last school which he attended ; also proof 

 of age. The next scholastic year of the Agricul- 

 tural College at Poona will commence on June 1, 

 1912, and the students nominated for the scho- 

 larship will be admitted to the College on ("hat 

 date. 



