REPORT OF THE COMMISSIONER OF AGRICULTURE. 11 



VI. Materials illustrating the utilization of wood by clry distillation. 



VII. Vegetable products prepared and preserved for food by special 

 methods. 



VIII. Products of the American materia medica, and the active prox- 

 imate principles separated from them. 



Besides the classes thus enumerated, our collection contains a series 

 of products illustrating the manufacture of butter and cheese. 



The fund at the disposal of the division for the purpose of following 

 out this plan was entirely too limited to make the collection complete, 

 but the materials obtained were so arranged as to illustrate as clearly 

 as they would the manner of their utilization. In some cases samples 

 were analyzed, and the results attached to them when exhibited, but 

 this could not be made universal. The analytical work done in this con- 

 nection constituted the bulk of the work done in the laboratory during 

 the past year, ^mong the materials analyzed was a series of samples 

 of excrements of bats found in caves distributed through the Southern 

 States. These samples were collected and forwarded by correspondents 

 of the Department, to whom circular-letters, asking for them, had been 

 addressed. Of the number furnished, ten were found to be worthy of 

 analysis, and of value ranging from $10 to $55 per ton, calculated upon 

 the basis of the values of their several constituents generally adopted 

 by analysis of commercial fertilizers. 



According to the reports received from our correspondents, the de- 

 posits represented by these samples are, some of them, of very great 

 extent. It is, therefore, a matter of considerable interest to southern 

 cultivators, especially of the inland States, where cost of fertilizing ma- 

 terials, depending upon transportation, is such an important item. 



We also collected a series of specimens of materials known to be, and 

 many supposed to be, of value for tanning. Of these materials thirteen 

 varieties were obtained, and in all of them the percentage of tannin 

 present was estimated. The work shows our range in the varieties of 

 materials of value in this particular to bemuch greater than is generally 

 supposed, and also that our national resources in this regard are prob- 

 ably greater than those of any other government. 



Our collection contains, further, a series of samples of native wines, 

 contributed by Bush, Son & Meissner, of Bushberg, Mo., which series 

 includes wines manufactured from several new varieties of grapes, be- 

 lieved to have special merit as material for manufacture of wine. The 

 number of samples (all of which were analyzed) obtained from this 

 source amounts to 22. The results of their analyses will be duly pub- 

 lished in our reports. 



There are still other materials of value, that were obtained while mak- 

 ing our collection, well worthy of analysis, the composition of which 

 shall be determined hereafter. 



The Microscopical Division of this Department has been principally 

 engaged in preparing a large collection of finely-executed water-color 



