April i, 1884.] 



THE TROPICAL AGRICULTURIST. 



733 



♦ 



To the Editor of the Ceylo7i Observer. 



ANALYSIS OF CINCHONA BARK. 



Colombo, 4th March 1884. 



Dkar Sir,— In last night's issue of the Observer, I 

 notice Mr. SyU-ester T. Richmond complains of a parcel 

 of Ballagolla Ella cinchona bark, consisting of 1,2S0 lb. 

 officinalis shavinsjs, having been analysed in Colombo 

 in September last with the result 1-09 per cent quimne 

 snlph., and that Dr. Tiul afterwards found it to contain 

 2'2 per cent or fully double the quantity. As a 

 Colombo analyst, permit me to state through your 

 columns tliat the analysis referred to was not made by 

 me. I find, however, that in November last I analysed 

 a parcel of 1,219 lb. Ballagolla Ella officinalis root and 

 stem chips and shavings with the result 2-31 per cent 

 quinine sulph. M. COCHRAN. 



[The analysis was made by the authority on whom 

 purchasers rely, as well they may if the results gener- 

 ally resembled those iu this case. There may be some 

 circumstances peculiar to the case, which it may be 

 well the public should know.— Ed] 



Colombo, 4th March 1884 

 Dear Sir,— Mr. Richmond's letter iu yesterday^s 

 issue publishes a solitary instance of a Colombo analysis 

 of bark having been lower than Dr. Pauls's. Allow 

 me to send you a list, supplied by a Crermau manu- 

 facturer, in his rejiort on bark shipped by my firm, 

 made of each lot by two analysts in which he gives 

 the averages of two separata analysts in his employ and 

 compares them with the Colombo analysis upon which 

 the bark was invoiced. 



Average of analyes Colombo averages, 



made in Germany. 



1-44 per cent 2-06 per cent. 



103 „ 1-12 



1-58 „ 1-96 



1-55 „ 1-95 



2-64 „ S-2i 



0-87 „ 1-32 „ 



1-75 „ 27s 



1-37 „ 2-05 „ 



0-79 „ 108 „ 



100 „ 1-48 „ 



0-74 „ 1-18 



3-52 „ 4'08 „ 



1-37 „ 1-66 



.1-34 „ 1-82 „ 



0-72 „ - 1-36 „ 



1-26 „ 1-66 



1-35 „ 1-82 „ 



319 „ 4-42 



0-S4 „ 1-97 



I may add, th.at another German manufacturer 

 found the Colombo an.alyses 30 per cent too high in 

 the two .shipments he received, and similar state- 

 ments have been made to me by several others. — I 

 am, sir, yours faithfully, PH. FREUDENBERG. 



CINCHONA BAKK ALKALOIDS. 



Theberton, Maskeliya, 7th March 1884. 



Dear Sir, — I have noticed in your prvper remarks, 

 on the difference of the analyses of cinchona bark 

 made in Colombo and London. The enclosed may 

 be of interest to your readers, showing the differ- 

 ence, also, of Colombo annlyses : — 



No. 30.1. — Analysis of Theberton renewed succirubra 

 ciuclxum bark, (ill trees 4 years old : — 



Crystallized sulphate of quinine .. 2'78 percent. 

 Total alkaloids ... ... 4-01 ,, 



No. 306.— Succirubra, original bark, off 4 years old 

 trees : — 



Crystallized sulphate of quinine ... 1'97 percent. 

 Total alkaloids ... ,., 6 14 per cent. 



Colombo, 3rd March 1883. 



Analysis, Theberton bark. Colombo, 29th Feb. 1884. 



Crystallized sulphate of quinine, net 1 '75 per cent. 

 Renewed and original succirubra chips from trees 3 

 to 5 years old. 



Succirubra original bark off trees 3 to 5 years old : 

 — Crystallized sulphate of quinine net 1'05 per cent. 



The above analyses were taken from a mixed lot 

 of bark, the larger portion of which was from trees 

 5 years old. — Yours truly, T. J. GRIGG. 



MR. WM. CAMERON'S DRIER. 

 Dear Sir, — I have been reading carefully over 

 Mr. Cameron's remarks in defence ot liis " drier." 

 It is iruo that I did not observe with .-ipproval the 

 fact, that he used a good deal of iron, to take the 

 heat out of the amoke, &c., in the flue. There are 

 also a great many other ingimious contrivances in 

 his plan, which I did not take note of by way of 

 expressing approval, It is not to be inferred from 

 that, that they are not excellent, or that I did not 

 think them so. I only noted what seemed to me 

 defects.* However it seems wc are agreed about the 

 superior advantages of iron over brick, as Mr. Cameron 

 e.xplaiuB that he only uses the brick flue in addition 

 to the iron covered one. 



I should doubt much, that it is any addition in 

 effect. If the iron has taken out all the heat of the 

 fire-heat in the flue, till the smoke, &c,, is reduced 

 to 120 inside the flue, be won't get mnch through the 

 brick flue afterwards to be of any service. And 

 if the air outside the flue, i. e. in the drying, house, be 

 hotter than smoke inside, the hiat will pass from the 

 air to the flue, more than from the smoke to the flue. 

 However, it seems to me that there are merits in 

 his scheme, if followed out in its main principle ; the 

 defect seems in trying to combine two different prin- 

 ciples that won't combine. A main feature of Mr. 

 Cameron's plan is to heat a large surface, and to lay 

 the bark to be dried on that surface to cjct heated 

 Now there is no question, that, if a damp thing 

 be heated, the moisture in it will get heated, 

 and evaporate ; and very little motion of air will 

 be needed to carry off the moisture evaporated. 

 The process is chiefly this. The hot surface heats the 

 bark on it and the miisture in the bark. The moisture 

 passes off into the air, and heats it, and is thus 

 carried upwards by cold air taking its place. A great 

 deal of drying can bo done, and is doue, in that way. 

 And in so far as Mr. Cameron's plan carries out that 

 procesB, it» merits are great. 



Drying by heated air has also much to recommend 

 it. Heated air gives out its hent slowly. Air heated 

 up to 200° or more would not burn the hand, while 

 water or iron so heated would. I am told tea will stand 

 heated air at 400°. Of course iron at that would burn it. 

 There is, therefore, not nmch danger of over-heating 

 a substance to be dried by hot air. A planter I knew 

 used to keep the air in his clerihew at 160°, and he was 

 not alarmed when it got to 180°a9 the coffee did not suffer; 

 Heated air holds more moisture than cold air, and 

 it is maintained that more advantage is gained by 

 using the air a high temperature, as equally great 

 or greater advantges are to be gained by heating 

 up a small qiiuutity of air to a higli temperaturo 

 than a largo quantity to a lower temperature. If the 

 drying effect is the same for fuel there is the advant- 

 age in time, and space, and mechanical power, less air 

 being required to be removed to effect the same 

 result. In drying by heated air, of course the sooner 



# True to humaa nature as well as to science. — Eo. 



