370 TRANSACTIONS OF THE 



during the day. We can raise the ostrich, by taking some pre- 

 cautions taught by experience. 



Silk from worms fed on the leaves of the castor-oil plant, is 

 considered likely to succeed. 



FISH PONDS. 



If in a pond of some five acres, suited to Carp, you desire to 

 obtain a great number of young fry, say to the number of fifteen 

 thousand, one male and one female, if there be no accidents, will 

 fill it amply. The young Carp cannot live in it beyond two to 

 three years, but at the end of that time they are superb; must be 

 taken out and a new stock put in. The fish are well elongated, 

 and of a beautiful yellowish, golden, brown color. 



GUM TRAGACANTH. 



By M. Sace, of the Society. 



This gum has the peculiar property of swelling in water with- 

 out dissolving, and forms one of the strongest adhesive matters 

 which we have. And as in drying it remains somewhat supple, 

 transparent and elastic, it is very useful for many purposes ; so 

 that within the last three years the amount of it used has nearly 

 doubled. Europe now uses about seventy-five thousand pounds 

 weight of it annually. This gum is the product of several spe- 

 cies of astragales, such as Milk vetches and Crow-toes, which 

 grow on the little hills of dry, calcareous soils in the Grecian 

 archipelago, and in Asia Minor, particularly in the vicinity of 

 Angora, of Caissar, of Yalavatz and of Bourdur. It appears that 

 the species which furnishes the best gum, are the Astragalus verus 

 and the Creticus. The gum oozes through the bark in the heat 

 of summer; it compresses all the thick sap under it. For a long 

 time we were contented to collect the gum where it was formed, 

 and it bore a very high price. Now we skin the bushes, and with 

 a keen knife make incisions lengthwise, through which the 

 gum oozes, which soon dries, and is removed in three or four days. 

 If it happens to rain at this time, or high wind throws dust on it, 

 it loses its first quality and becomes second. All the bushes are 

 not, therefore, cut at one time, so as to injure the whole crop. 

 These astragals will probably succeed in Algeria. 



