SCIENCE BULLETIN, No. 12. 



several " bone-chewing " soils had been analysed by Mr. F. B. Guthrie, with 

 the result that he came to the conclusion that the complaint was due in the 

 main to a deficiency of lime and phosphates in the soil. Accordingly a lick 

 was prescribed, consisting of bone-ash, salt, ferrous sulphate and molasses,, 

 which has proved effective in checking the complaint. The liming of the 

 worst affected paddocks has also been tried with success. 



The present more exhaustive investigation of soils from the affected and 

 unaffected areas fully bears out the conclusions already arrived at by 

 Mr. Guthrie. 



The unaffected areas consist mostly of dark-coloured soils, well supplied 

 with lime and possessing a porous subsoil. The affected areas have light- 

 coloured, poor soils, and clayey subsoil. In connection with this the writer 

 has noticed in various parts of the States of New South Wales and 

 Queensland that the bone-chewing habit is always most prevalent on geo- 

 logical formations like sandstones, aplites and granites, which yield silicious 

 sandy soils, poor in lime, and is absent on limestone, basalt, dolerite, diorite 

 and gabbro soils which are well supplied with lime. The following facts, 

 however, tend to render difficult the solution of the problem, and the cause 

 of the complaint: 



(a) For a large number of years the Moruya and Bega districts, with 

 their granitic soils, were free from the disease, but of late years 

 it has become rampant in parts; 



(6) Some of the affected areas in these districts have better soils than 

 unaffected areas in other districts; 



(c) The Bergalia Andesite soil from an infested paddock is compara- 

 tively rich in lime and phosphoric acid. 



How far the exhaustion of the cows by dairying in districts where formerly 

 breeding for the market was the industry, and how far the artificial feeding 

 of calves has created a tendency to disease, are matters for others to discuss, 

 but the soil itself in those affected areas which are not excessively deficient 

 in lime often shows certain peculiarities that deserve special mention. 



The surface 4 inches of soil in bone-chewing areas is often exceedingly 

 hard, almost as hard as cement, so that a pick must be used to break it up. 

 The subsoil is also rather hard, lumpy and dry. The causes of these 

 peculiarities are probably, first, the clearing or ringbarking of the country, 

 and, secondly, the continued tramping of cattle on the ground. 



Clearing or ringbarking has the effect of destroying the life of those large 

 tree-roots whose growth causes constant breaking up and aeration of the 

 subsoil. The humus percentage of the surface soil, which, in the natural 

 state, keeps it in a loose and aerated condition, is greatly reduced by the 

 absence of decaying leaves and grass; for the trees are now' gone, and no 

 longer yield the former, and the grass is eaten by the cattle as fast as it 

 grows. Absence of vegetable matter and the constant trampling leads to the 

 surface soil forming a hard crust, which is probably further cemented by 

 salts drawn up from below by capillarity. 



