268 BOARD OF AGRICULTURE. 



The samples which served for these analyses were stated 

 to have been taken from three different deposits in Texas. 

 The first information regarding such deposits within the 

 country I received at an early date in 1875, through a letter 

 from a party in Austin, Texas. The following description 

 was given : — 



" The lands upon which the bat deposit is located are situated 

 on the southern line of Llano County. The deposit exists in a cave 

 in carboniferous limestone, and extends about three-quarters of a 

 mile into the mountain ridge, where it is made by millions of bats 

 covering the ceiling and walls of the cave. The guano looks like a 

 sample of Peruvian guano now before me. A superficial examina- 

 tion has convinced me that it contains a considerable proportion of 

 nitrate of lime. Exposed to moist air it becomes sour ; the floor 

 of the cave, which consists of limestone, is everywhere impregnated 

 with nitrate of lime. During the war, it is stated, attempts were 

 made to turn the guano and its surrounding limestone to account for 

 the manufacture of saltpetre for gunpowder. The deposit amounts 

 to at least one thousand tons." 



Professor McMurtrie, the able chemist to the National 

 Department of Agriculture, has published in the department's 

 report of May and June, 1876, a very interesting paper on 

 the occurrence of bat guano deposits within the United States. 

 According to his statement they are quite numerous, extend- 

 ing over an extensive area from Virginia to Texas. Short 

 descriptions are given of deposits in Virginia, Kentucky, 

 Tennessee, Alabama, Arkansas and Texas. The analyses of 

 samples from seven different deposits show a great variation 

 in composition and value ; the latter varies from $15 to $55 

 per ton. The variation is largely due to differences in moist- 

 ure (from 2.5 to 44 per cent.), and to admixtures of sand, 

 etc. (from 0.46 to 62 per cent.). The main constituents of 

 a bat guano are the excretions of these animals, which con- 

 sist largely of the wings and other scaly parts of the insects 

 they feed on, besides the remnants of decaying bats. The 

 large amount of nitrogen which the former contain causes 

 the value of the bat guano in most instances. Bat guano has 

 been used for years for agricultural purposes in Europe and 

 elsewhere. Large deposits have been found in Poland, Hun- 



