578 
THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. [January 13, is:?. 
formation of the radiate layers (Wigaud’s) is of great 
interest; every single one is a complete system, repre¬ 
senting the construction of a dicotyledonous axis, consist¬ 
ing of phloem, xylem and cambium; the last is often 
visible to the naked eye as a dark ring; strange to say, 
the parts of the phloem, viz. the liber and the cortical 
rays, are inside the cambium, while the parts of the 
wood, viz. ligneous and pithy rays, are outside; this 
is a distinguishing mark from the drug cultivated in 
Europe. 
The cells of the pithy rays and of the ligneous paren¬ 
chyma carry the active and colouring principles, and the 
last also starch; the first show under oil a lumpy bright 
yellow or orange-red mass, sometimes divided into several 
angular or round fractures, in the adjoining cells of the 
ligneous parenchyma a yellow bag encloses the starch. 
Solution of iron colours the yellow lumps and hags 
first green, afterwards deep blue; in water they break 
up with yellow colour into molecular grains ; glycerine 
dissolves them with yellow colour. Alcohol produces in 
the cells of the pithy rays enclosed in a light yellow hag 
reddish-brown bubbles, which gradually dissolve to a 
yellow solution, especially on addition of water; solution 
of iron then produces a blackish-blue precipitate of a 
fine grainy or flocculent nature; ether dissolves part of 
it with yellow colour, potash with splendid blood-red 
colour. 
The purgative constituent of rhubarb is, according to 
Yon Schroff, chrysophanic acid (C 20 H 8 O 6 ), a yellow, 
crystalline substance without taste or smell, soluble in 
alcohol and ether with yellow colour, and producing with 
alkalies a solution of a splendid dark red colour. 
. The root contains also three resinous substances, a full 
investigation of which is still wanting; these are ery- 
throretine, phaecretine and assoretine. Alkalies dis¬ 
solve the first with purple colour, the second with red¬ 
dish-brown colour, and the third with dark brown colour; 
the first is soluble in alcohol and ether, the last is inso¬ 
luble in ether. Warren de la Rue and H. Mueller se¬ 
parated also emodine, a red crystalline resin, soluble in 
benzole. 
All these substances form, together with tannin, the 
sole contents of the cells of the radiate layers and part 
of the contents of the adjoining ligneous parenchyma. 
Starch is present in globular, mostly in regular forms, 
of about 0-012 to 0‘016 mm. diameter. 
Besides the above substances, sugar, pectine, wax, fat 
and traces of an essential oil have been found in the root; 
the ash amounts to 13-87 per cent., 7‘33 per cent, of 
which is oxalate of lime ; the remainder, carbonates of 
potash and lime, and alumina and magnesia. 
It is doubtful whether the Rhaponticum of the ancient 
Greeks and Romans is our Rheum rhaponticum, also 
whether rhubarb was at all known to them. 
European rhubarb is sometimes substituted, but may 
be easily distinguished as stated above. Last century 
experiments were made in different countries to cultivate 
rhubarb, several varieties were planted, as R. rhaponticum, 
R. palmatum, R. undulatum , R. compaction and others ; 
almost every one was for a time considered to be the 
genuine rhubarb plant, and hopes were raised to become 
independent of the expensive Russian drug. But the 
products differ mostly in outer appearance, but more 
so in the absence of the pithy veins. 
They are brought into the market decorticated, often 
rubbed with genuine rhubarb powder, and sometimes 
even with holes bored into the pieces. The surface is 
generally more yellowish-brown or reddish-white, with 
extended strings of vesicles instead of rhomboic meshes. 
The section of European rhubarb shows the white or 
whitish-red primary mass, interrupted by red or reddish- 
brown rays, starting from the circumference towards the 
centre, without the least indication of a mark layer, and 
hence, without separation of the remaining part into a 
central mass and a zone surrounding the mark layer. 
This regular structure is also visible on breaking a 
piece; even the centre of the largest pieces never show 
the marbled appearance, due to the irregularity of the 
rays and the presence of many spots; this difference is 
highly characteristic; the structure of European rhu¬ 
barb is, as a rule, looser, soft, uniformly white or yellow, 
with many red or red-brown specks. Smell and taste are 
similar to those of genuine rhubarb, but weaker, the same 
active principles being present, but in much smaller 
quantity; starch is more predominant in the single struc¬ 
tural elements of the European root, but the form of it3 
grain and that of the oxalate of lime are the same as those 
of the Chinese rhubarb. 
Most reluctantly do we close this book, which more 
than confirms the well-known advanced position of Dr. 
Yogi as an original investigator and microscopist; he 
is the first to show strict characteristics of vegetable 
drugs, drawn from the structural conditions as shown 
under the microscope. We have already pointed out 
that the book really is much more than a commentary to 
part of the Pharmacopoeia, inasmuch as it treats with, 
great completeness nearly as many non-officinal as offi¬ 
cinal drugs, and it may in fact be considered one of the 
best books ever written on pharmacognosy. 
The second or chemical part of this volume, written by 
Dr. Schneider, will form the subject of our next commu¬ 
nication. 
PROFESSOR BLYTH. 
Dr. Blyth, the distinguished chemist and lecturer, has 
just died. Born in Jamaica, in 1814, he was, in early 
life, a student of the University of Glasgow, and spent, 
subsequently, several years in France and Germany, 
acquiring scientific knowledge under the most eminent 
foreign lecturers. In 1845, on his return home, he was. 
associated with Dr. Hofmann in the establishment of the 
Royal College of Chemistry, and in 1847 was appointed. 
Professor of Chemistry at the Royal College of Ciren¬ 
cester. On the death of Mr. Gregory, Professor Blyth 
was chosen by Baron Liebig as editor of his works in 
England, and finally settled in Ireland. 
MEETINGS FOR THE ENSUING WEEK. 
Monday . Medical Society, at 8 p.m. 
Jan. 15. London Institution, at 4 P.M. —“ Elementary 
Chemistry.” By Professor Odling. 
Tuesday . Royal Institution, at 3 p.m. —“On the Ner- 
Jan. 16. vous and Circulating Systems.” By Dr. 
Rutherford. 
Wednesday ...Society of Arts, at 8 p.m. 
Jan. 17. London Institution, at 7 P.M. —Conversa¬ 
zione. 
Thursday . Royal Society, at 8.30 p.m. 
Jan. 18. Royal Institution, at 3 p.m. —“ The Chemistry 
of Alkalies and Alkali Manufacture.” By- 
Professor Odling. 
Linnean Society, at 8 p.m. 
Chemical Society, at 8 P.M. 
Friday . Royal Institution, at 9 p.m. —“On the New 
Jan. 19. Metal Indium.” By Professor Odling. 
Saturday . Royal Institution, at 3 p.m. —“ The Theatre 
Jan. 30. in Shakspeare’s Time.” By W. B. Donne- 
The following journals have been received:—The ‘British 
Medical Journal,’ Jan. 6; the ‘Medical Times and Gazette/ 
Jan. 6; the ‘Lancet,’ Jan. 6; the ‘Medical Press and Cir¬ 
cular,’ Jan. 10; ‘Nature,’ Jan. 6; the ‘Chemical News/ 
Jan. 6; ‘English Mechanic/ Jan. 5; ‘Gardeners’ Chro¬ 
nicle,’ Jan. 6; the ‘Grocer/ Jan. 6; the ‘Journal of the 
Society of Arts,’Dec. 30; the ‘ Practitioner’for January; the 
‘ Doctor’ for January; the ‘Food Journal’ for January. 
