"GROUSE DISEASE " COCCIDIOSIS 265 



Salt produces plasmolysis in the end ; but the process is rather slow, and the 

 salt is too readily dissolved in dew and rain, and so merely soaks into the soil. 1 



Quicklime destroys the oocysts and sporocysts. It also causes the faeces to 

 cake, thereby preventing scattering of the spores. It is somewhat doubtful whether 

 lime could be applied on a large scale. It might be somewhat harmful to the feet 

 of the birds, apart from the difficulty of distributing it over large areas. Where 

 the area of infection is small, it is probable that the application of lime to the 

 soil would be of service. My experiments on a small plot of heather at Cambridge 

 have shown that small quantities of lime dressing are not detrimental to heather. 



Gas lime and slaked lime also are useful, but each is open to the same objec- 

 tion as quick lime. Lime in one form or another certainly seems to have the best 

 and most rapid action on coccidian oocysts of any reagent that I have tried. 



Salicylates. Salicylic acid and sodium salicylate act rather slowly on coccidian 

 oocysts when mixed with them. Both chemicals tend to deliquesce, and the faeces 

 mixed with them remain fluid for a longer period than they otherwise would. 

 The oocysts become wrinkled and ultimately destroyed, but the contents take 

 longer to degenerate than when lime is used. 



Ferrous Sulphate. Copperas or green vitriol is useful to some extent in destroy- 

 ing coccidian oocysts, but like salicylates it is somewhat slow in action. A dusting 

 of ferrous sulphate on the moors would probably be beneficial, for the combined iron 

 present might be taken up in small quantities by Grouse and, by acting as a general 

 tonic, might enable the birds to resist Coccidiosis the better if they became 

 attacked. Ferrous sulphate in the proportion of 10 grains to the gallon of drinking- 

 water has been found of service by the writer in the treatment of Coccidiosis in 

 young fowls and young Pheasants. Some keepers and breeders, at my suggestion, 

 have used catechu in the drinking-water with success. 



Sodium Nitrate. Nitrate of soda mixed with fasces destroyed the contents of 

 the oocysts after some time, but the length of time required for its effective 

 application would militate against its use on a large scale. 



In my experiments at Cambridge, three portions of infected faeces were mixed 

 with equal quantities of lime, sodium salicylate, and ferrous sulphate respectively, 

 and were kept in open dishes, exposed to the action of the weather. The results 

 obtained may be shortly given. 



In the case of lime, the faeces rapidly formed a caked mass. In a fortnight 



1 However, in this connection see Hammond Smith, The Field, August 20th, 1910. Suppl. p. viii. 



