RAVAGES OF OTHER LOCUSTS IN THE UNITED STATES. 443 



condenser was found to be 145 cubic centimeters of a colorless, limpid solution of 

 formic acid (CHiOc) having a specific gravity of 1.0056. Though this acid exists in 

 the red ant {Formica rufa), from which it was originally obtained, and in the larvae of 

 some species of Bomhyx, we are to understand that in the present instance it is gene- 

 rated by the action of the sulphuric acid upon the decomposing locust-extract. We 

 know that formic acid may be manufactured by similar distillation of a large number 

 of organic materials with sulphuric acid and peroxide of manganese ; but in the case 

 of the locust-juice at this stage of decomposition the formic acid passes over with 

 great readiness, and in remarkable quantity and gravity. Formic acid has a present 

 market-value of about 60 cents per ounce. In the form of the free acid, as formic ether 

 and as formates of ammonium, sodium, &c., it has been employed by English practi- 

 tioners as a therapeutic agent of considerable value. Free formic acid and formate of 

 sodium are frequently employed as laboratory reagents, and are exceedingly useful 

 f jr their great reducing power upon salts of the noble metals, silver, gold, and plati- 

 num. By the use of sodium formate a peculiar form of xjlatinum black may be obtained, 

 of great power in inducing combustion. From its reducing property this salt also con- 

 stitutes a very convenient reagent in blow-pipe analysis. The various uses of formic 

 acid in all these departments are undoubtedly capable of great and valuable extension, 

 should it ever become a common article of manufacture. It is not, therefore, impossi- 

 ble that the very ready preparation of such large quantities of this acid from the 

 Caloptenus spretm may be found in time to have a practical bearing should the only 

 satisfactory solution of the locust problem be found to depend on some profitable dis- 

 position of the locusts themselves. 

 Very respectfully, yours, 



WILLIAM K. KEDZIE. 

 Prof. Charles V. Riley, 



Chief United States Entomological Commission. 



As a manure, it is obvious that wherever locusts occur in destructive 

 numbers, they may be collected by hand or by machiues, killed, and 

 buried in trenches or in compost heaps, and thus utilized. Mr. L. S. 

 Burbank, of Woburu, Mass., has suggested that locusts might be col- 

 lected in large quantities, dried, and sent east, in bales, as food for 

 poultry. 



CHAPTER XVIII. 

 EAYAGES OF OTHEE LOCUSTS m THE UNITED STATES. 



RAVAGES OF LOCUSTS THAT ARE OCCASIONALLY MIGRATORY IN THE 



ATLANTIC STATES. 



While this report is essentially devoted to the true, migratory locust 

 west of the Mississippi, it is not only desirable but necessary to draw 

 brief attention to the ravages of other species in various portions of the 

 country. The differences have already been pointed out between the 

 Rocky Mouutain Locust, which does not occur er.st of the Mississippi, 

 and the Red-legged and Lesser species often found with it. We have 

 further seen that the region of country between the Mississippi and the 

 Rocky Mountains, and much of that west of the mountains, is ravaged 

 by the longer-winged species alone (spretus), and it becomes us to ac- 



