82 REPORT OF THE COifMISSIONER OF AGRICULTURE. 



2. In October, some of the females, after metamorphosis, takinrj flight from the 

 ground, ascend to the stems of the vines, where they deposit their eggs. 



3. The eggs, which are called winter-eggs, are hatched in the spring. 



Yours, &c., 



. c. jaquI:me. 



The specimens of Phylloxera vastatrix alluded to arrived safely, and I 

 mounted the best of them in balsam. Ha^^ing good specimens of the 

 American Phylloxera on hand, I selected two of them and also two of 

 the foreign species, and had them photographed. The French Phylloxera 

 appears to be smaller than the American. The same objective was used 

 for both specimens, and they seem to be identical. Photographs have 

 been forwarded to Dr. C. Jaqueme, Marseilles, France. Since the receipt 

 of the specimens no opportunity has occurred to enable me to make any 

 outdoor examination of the habits of the American Phylloxera', and, 

 moreover, the grape-vines of this section of our country are seldom 

 injured to any appreciable extent by this insect. 



Fig, A represents a top view of the French Phylloxera vastatrix, and 

 B a profile of the same; and C and D represent two views of the American 

 Phylloxei-a. 



EUCALYPTI. 



The preservation of medicinal alkaloids from fermentation is a sub- 

 ject of much interest to the medical fraternity, hence the following 

 inquir}- addressed to the Commissioner of Agriculture by Dr. Wm. H. 

 Eoss, of this city : 



1019 F Street, N. W., 

 Washington, IJ. C, December 11, 1876. 

 Sir : My attention havinfc been lately cnlled to the properties of infusions of leaves 

 of Eucalypti to preserve medicinal alkaloids from fermentation, I would suggest that 

 this bo made a subject of examination by the ilicroscopist of your Department, with a 

 view to ascertain their general bearings as an autifungoid and deodorizer. 

 Very respectfully, ^ 



WM. H. ROSS, M. D., 

 Professor of Materia Medica and Therapeutics, University of Georgetoivn, D. C, 



In consideration of the preceding request, I made a series of experi- 

 ments with eucalyptol and other essential oils, as follows : Twelve 

 glass jars, each hokling one quart, were arranged side by side. In six 

 of them I placed a quantity of the leaves of several species of the Eu- 

 calyptus, taking care that each jar should contain the leaves of a dis- 

 tinct species. The jars were then filled with pure water. Ground stop- 

 pers were used to exclude air and dust from the solution. Each jar was 

 numbered, respectively, from one to six, iN'o, 6 contained leaves of the 

 Eucalyptus (jlohulus. Seven other jars, numbering from seven to tbir- 

 teen, were filled with solutions, and various plant-leaves, as follows : 

 No, 7 contained a solution of sulphate of quinine in the proportion of 

 about 3 per cent, of the alkaloid. In this solution I immersed a foreign 

 grape-leaf, No. 8 contained a grape-leaf and pure water ; x>o. 9, a grape- 

 leaf and pure acetic acid; Xo, 10, equal parts water; Xo, 11, a large 

 cinchona-leaf and a weak solution of the essential oil of the Eucalyptm 

 globulus, made by immersing a few leaves of that plant in pure water, 

 by which the water became impregnated with the oil. Xo. 13 contained 

 water, a grape leaf, and about half an ounce of the Uowers of sulphur. 

 At the termination of ten days I found that nearly all the plant-leaves 

 had fermented ; the exceptions were those contained in numbers 6, 9, 

 10, 11, and 13. Although eucalyptol oil is very sparingly soluble in 

 water, its weak solutions prove highly antiseptic and deodorizing; and 

 when the amount of albuminoids held in solution is reasonably limited, 

 they are preserved. Solutions of the alkaloids^ and some of their medic- 



