On Tj Argus and Juioiter's Spectrum. 23 



than is generally believed : the Plenty river, at its source in 

 the ranges where the water first oozes out of the mossy 

 ground, alr-eady shows evidence of chlorides in solution ; 

 the clay, in situ, at the Old Exhibition Reserve, in which 

 the sample of gaspipe exhibited has decayed, retains 

 13 oz. of salt, at least, per cubic yard, although it is of a 

 highly porous character, although situated at one of the 

 highest levels in Melbourne, and doubtless after occupying 

 its present position high above the sea for a long continuance 

 of centuries, subject all the time to the influence of rain 

 soaking into it, and having a greater or less power of 

 dissolving and removing the salt. It is true that the 

 subsoil partakes something of the nature of a barrier, the 

 drainage escaping in many cases over it rather than through 

 it, so that soluble saline matters travelling down into the 

 subsoil may be thus cut off from the further transporting 

 influence of drainage. 



I will close these statements and suggestions with an 

 incidental remark concerning the salting of land — namely, 

 that it does not necessarily follow that the salt is in all cases 

 derived directly from the sea, that the salt is that which 

 was in the soil or clay or rock at the time when it formed a 

 sea bottom, and was submerged in brine. The atmosphere 

 may be ascertained to perform an important office in this 

 respect intermediate between the sea and the land. There 

 is reliable evidence that the atmosphere performs this func- 

 tion in some degree. To measure the extent to which the 

 air acts as a distributor of sea-water constituents over the 

 land would be a work replete with interest. It is a question 

 which may prove itself closely related to the sciences of 

 hygiene and agriculture, and even with geology. 



Aet. V. — On 7} Argils and Jupiter's Spectrum. By 

 A. Le Sueur, Esq. 



[Eead 14th March, 1870.] 



I take this opportunity of mentioning that since the last 

 meeting, the star -q Argus has been examined with the 

 original apparatus, modified so as to admit of a larger 

 dispersion. 



With this new arrangement the red line keeps its ]jlace 

 and character, the yellow is seen to be slightly less refran- 

 gible than D. 



