TRANSACTIONS OF SUB-SECTION K. 



601 



Higher multiples may be obtained by changing the vowel in cental, viz., 

 cental, 100 lb.; centel, "lOO 2 lb.; centil, 100' lb. (million); centol, 100 4 lb.; 

 cental, 100 5 lb. ; centyl, 100 5 lb. (billion). Numbers could be very simply 

 reduced to centals, &c. ; e.g., 2,347 lb. equals 2 tuns, 3 centals, 4 dekeis, 7 lb. 



Useful connections with existing Weights. — The multiples would be mostly 

 need in agriculture, trade, commerce, science (hydrostatics), &c. , and need cause 

 little trouble, seeing that the unit employed is still the same. The score (20 lb.) 

 is a common weight in agriculture, and the quarter (480 lb.), boll (240 lb.), 

 pack (240 lb.), and windle (220 lb.), are usually expressed as so many 'scores.' 

 Five scores equal 1 cental, and 1 score equals 2 dekeis. The cental is used 

 already in this country (Liverpool and Manchester) and in America. A cental 

 would be approximately the weight of a good ' hogg ' or ' teg,' and ten times 

 this (one tun) about the weight of a store bullock. The 'dekel' (10 lb.) is the 

 weight of a gallon of water, which would be a useful ' derived ' weight in 

 physical science. 



2. Sub-Mvltiplrs. 



The above-named are derived from the corresponding words used as multiples, 

 and consist of the latter part of each word employed. Further subdivisions, 

 if necessary, with exceedingly rare chemicals could be obtained in the same way 

 as the higher multiples ; e.g., tal, 1/100 lb.; tel, 1/1002 lb.; til, 1/100 3 lb., &c. 



The adoption of this system would affect the apothecary, jeweller, &c, but 

 the difficulties would be more apparent than real, as a small table of equivalents 

 would give the necessary information; e.g., the grain is of the same value 

 troy, apothecaries', and avoirdupois, and is in use in most countries. It will be 

 seen at a glance that 7 grains are equal to 10 tels ; 1 grain is therefore very nearly 

 equal to I5 tels. The drachm avoirdupois is ^j. lb., and is approximately equal 

 to 39 uns. The ounce avoirdupois (437^ grains) is the one used in the British 

 Pharmacopoeia, and is equal to 6"25 tals. 



With the grain common to troy, apothecaries', and avoirdupois weights it 

 would appear possible by a little united effort to establish a uniform decimal 

 system of weights of the greatest possible advantage. 



F BID AY, SEPTEMBER 1. 



The following Papers were read : — 



1. Discussion on Bacterial Diseases of Plants. 



(i) Bacterial Diseases of Plants. By Professor M. C. Potter, M.A. 



The existence among plants of diseases which are caused by the invasion of 

 parasitic bacteria is a fact which will hardly be disputed in the present day. A 

 preconception once widely held, that the special features of plant structure, the 

 nature of the cell-sap, and the impervious character of the cell-wall rendered the 

 plant organism impregnable to bacterial attack, has been shown to be entirely 

 erroneous ; and it has been abundantly proved, under rigid conditions of experi- 

 ment, that certain bacterial diseases of plants could be reproduced in healthy 

 tissues with absolute certainty, and would develop the characteristic pathogenic 

 symptoms as surely as any of the most virulent forms of animal parasite. 



The plant possesses many vulnerable points of attack, and infection has been 

 shown to take place through the water-pores, the stomata, the floral nectaries, 

 and through wounds, the vessels of the xylem affording a suitable channel for the 



