1888.] Address. 67 



botanical subject, another of Dr. Cunningham's researches merits 

 notice here, as it is one in which every inhabitant of the Gangetic 

 delta is practically interested. Dr. Cunningham, in his memoir on the 

 nature of the sub- soil of • the neighbourhood of Calcutta, shows that 

 this soil is singularly porous in texture ; and that, in a cubic foot of it, 

 there is an air space equal to from one-fourth to one-third of its entire 

 bulk. When the air in this space is replaced by water, the mass as- 

 sumes a superficial resemblance to clay, although in fact it is a mixture 

 of sand and water in the proportions just stated. 



I may also mention here that the ' Journal of the Bombay Natural 

 History Society ' contains interesting papers, by Mr. Bird wood, on the 

 flora of Maha.bleshwar and Matheran with a vernacular index, and 

 by Dr. Dymock on the Marathi names of plants. In the ' Annals,^ also, 

 we have a useful paper by Mr. G. Murray on the ' Ceylon Algae in 

 the Herbarium of the British Museum.' 



Geological Survey. Economic. — The most important economic work 

 of the Geological Survey during the year has been the examination of 

 the auriferous tracts of Mysore by Mr. Foote, who reports on all its 

 known gold localities and their capabilities. The more interesting 

 geological feature of his work lies in the fact that he has recognized a 

 transition series to which in Mysore, and in the country on towards 

 Dharwar, the gold bearing reefs are confined. This Dharwar series 

 may eventually turn out to include some, if not all, the many transition 

 groups of the northern portion of the peninsular area of India ; and 

 it is to be noted at the same time that the more decidedly metalliferous 

 deposits are confined to such transition rocks rather than to the great 

 crystalline or gneissic series. The next most interesting ore tract is 

 that of the manganese and iron near Jabalpur, which is again under 

 examination by Mr. Bose. Several new features have been noted which 

 may lead to a larger estimate of the distribution and, perhaps, extent of 

 the manganese ores than that put forth by Messrs. Medlicott and Mallet 

 in their original reports. 



The estimate of the capabilities of the Chhatisgarh coal field re- 

 mains unchanged, though a seam of workable coal has been discovered 

 and proved in one place near Korba. The example of the Mohpani 

 colliery, however, shows how necessary it is to carefully examine a 

 seam before expensive works are undertaken ; and, here also, it would 

 be very hazardous to commence operations until further borings are made. 

 With regard to the other great coal areas in Chhatisgarh, which have 

 as yet given most indifferent and, in some cases, unreliable boring assays, 

 a few trial pits to test the coal in bulk are about to be carried out, 

 Mr. Oldham's further explorations in Rajputana have not yielded any 



