26 ODOROGRAPHIA. 
glands. The sepals are very pointed and sometimes 3 centimetres 
in length. The margins of the two exterior sepals and the 
exterior margin of the partly exposed inner sepal of the bud are 
provided with several long thin tongue-like growths, covered with 
hispid glands on the outer surface. The two sepals and the sepal 
partly concealed in the bud are simply hairy. The internal surface 
of the five sepals is covered, towards the broad concave base, with 
a fine pale down. The petals are orbicular, pink, almost red in 
the bud, and becoming paler as the flower expands; they are thin, 
not shiny, but not velvety. The stamens are few innumber. The 
styles are free in their entire length. The exquisite odour of the 
flower is very analogous to that of the R. centifolia. The colour 
of the berry is cherry-red. 
A microscopic examination of the transverse section of a rose 
petal reveals that the otto is secreted in cells on both its surfaces, 
those of the upper epidermis being of a papillary form and those 
of the lower of an elongated cubic form. The presence of the 
oil in these cells is clearly demonstrated by moistening the section 
with a dilute aqueous solution (1 in 200) of osmium tetroxide 
(OsO,, sometimes called osmic acid); a reagent of great sensi- 
tiveness in detecting the presence of both essential and fixed oils, 
The section becomes almost instantaneously bordered by two 
bluish-black lines of cells, resulting from the reduction of the acid 
and deposition of the osmium*, The section must be then washed | 
in distilled water and mounted in glycerin. 
Information respecting the cultivation &c. of the rose in Bulgaria 
was published by D. Pappazoglou of the firm of Pappazcglou 
Brothers of Kézanlik, and issued in the form of a pamphlet at the 
Philadelphia Exhibition, where the firm exhibited specimens of 
their otto. Later information on the subject has also been pub- 
lished by Christo Christoff, also a merchant of Kézanlik, and an 
exhibitor of otto at the Paris Exhibition, 1889. These two 
pamphlets contained much useful information which is to a great 
extent embodied in the following details of the culture of the 
rose in Bulgaria :— 
The bushes are planted close together, so as to form hedges, in 
long parallel rows, with a space of about six feet between the rows. 
The bushes grow about six feet high. 
The ground selected is preferably of a sandy porous nature 
* Blondel, in Bull.de la Soc. Bot. de France, Feb. 1889. 
