2 2 2 THE NA TURE-S TUD V RE VIEW 



[2 : 6 — sept., 1906 



Artificial Coloring of Flowers. Professor Kraemer, of Philadelphia, 

 has been experimenting with aniline dyes and finds that manv of them in 

 solutions ( 1 part dry dye to 1000 parts water) will color white flowers if the 

 cut flower stalks are allowed to stand in the solution one or two hours and then 

 transferred to water. Some species of flowers take up the dyes readily. A 

 remarkable fact is that only a few of the thousands of kinds of aniline dyes 

 give good results in such artificial coloring. The best dyes are the following, 

 which could be ordered from dealers in chemicals: yellow, the commercial 

 "acid yellow A. T.;" orange, "orange G. G. ;" blue, "cyanol F. F. ;" 

 green, equal parts of the dyes for yellow and blue; purplish-red, "acid 

 magenta;" crimson, equal parts of "acid yellow A. T. " and "acid magenta;" 

 purple, equal parts of "cyanol F. F." and "acid magenta;" gray, "naphthol 

 black B." Carnations will take up colors from the soil without injury to 

 odors or plant. These experiments open up an important line for floral deco- 

 rators who frequently find difficulty in producing the desired color groups 

 with natural flowers. {Bulletin Torrey Botanical Club, ^l'- 77~92. 

 1906.] 



Diseases of Rodents. The Bureau of Biological Survey, United States 

 Department of Agriculture, has issued a circular letter as follows: It is well 

 known that many species of rodents which live in colonies, such as prairie 

 dogs, rabbits, spermophiles, field mice, and rats, are subject at irregular inter- 

 vals to microbic diseases in the nature of epidemics, which greatlv reduce their 

 numbers. The Department of Agriculture desires to be informed of the 

 presence of such epidemics with a view to isolating and preserving the mi- 

 crobes for use in destroying mammals injurious to agriculture. You will greatly 

 oblige, therefore, by informing the Department of the presence, in your neigh- 

 borhood, of epidemic diseases among wild mammals, now or at any future 

 time. Such diseases are usually indicated by the presence of numerous sick 

 or dead animals. 



Fire Fighting on the National Forest Reserves. The worst enemy 

 of the forests is fire. To combat it the Forest Service maintains a fire fight- 

 system. How effective is this system is shown by the following 

 figures for the last two years: The area of forest reserves in the United States, 

 exclusive of Alaska and Porto Rico, was on January 1, 1905, over 58 million 

 acres and nearly 390,000 acres had been burned over. One year later the 

 reserve area had been almost doubled, the burned area had been reduced by 

 more than one-half, and the percentage of area burned had been reduced by 

 more than three-fourths. 



Only since February 1, 1905, have the reserves been under the adminis- 



