148 
LEEDS chemists’ ASSOCIATION’. 
quinine, peculiar fluorescent properties. He adopted Professor Stokes’s test, in which 
an acid or alcoholic solution of the bark is placed in a glass tube surrounding a small 
Geissler’s vacuum tube, and the spark from a Kuhmkorff’s coil is passed through it. If 
quinine, or any other substance having fluorescent qualities, be present, these are in¬ 
stantly developed. Mr. Stoddart’s experiments upon twenty-seven samples of_ barks 
occupied but two hours, showing a great advantage over chemical methods in the 
element of time. Messrs. Deane and Brady have struck out a new path, by combining 
microscopical with chemical research, and the fruit they have already culled from such 
fields may convince* us that rich harvests await patient investigators. 
Again : Cannot electrical phenomena give us some further aid ? The resistances to 
electrical discharges offered by fluids vary greatly, being the reciprocals of their conduc- 
iive powers. 
Here is a table of resistances:— 
Pure Silver. 1 
Mercury. 29 
Sulj)liuric Acid. 761,732 
(Sp. gr. 1-2 to 1’3G.) 
Solution Sulphate of Zinc.11,019,000 
(38 p. c. Salt.) 
Solution Sulphate of Copper .... 14,809,000 
(20 p. c. Salt.) ( Watts’ Diet. Chem.) 
The resistance of distilled water is 700 times greater than that of dilute sulphuric acid. 
I have alluded to castor-oil as a medicine whose repute is probably waning, but if any 
old familiar friends of the shop seem falling in public favour, there axe new candidates 
for its somewhat fickle preference. Thus, T^'iticum repens has insinuated its rhizomes 
into modern pharmacy with as much pertinacity as into the fields of our farmers ; and 
yet couch-grass is no new medicine. Gerarde says of it,—The decoction of the root 
is good for the kidneys and bladder,” and expressly alludes to “ the learned physitions of 
the Colledge and Societie of London ” as recognizing its merits. But the most caustic 
reproof to inconstant physicians is given by the same author, when speaking of the herb 
Golden Kod (^Solidago Virgaured). He says:— 
“ In my remembrance I have knowne the dry herbe which came from beyond the sea 
sold in Bucklers Bury, in London, for halfe a crowne an ounce. But since it was found 
in Hampstead wood, even as it were at our towne’s end, no man wdll give halfe a 
crowne for an hundred weight of it: which plainly setteth forth our inconstancie and 
sudden mutabilitie, esteeming no longer of any thing, however pretious soever it be, 
than whilst it is strange and rare. This verifieth our English proverb,—‘ Far fetcht 
and dear boughte is best for Ladies.’ Yet it may be more truely said of phantasticall 
Physitions, who when they have found an approued medicine and perfect remedie neere 
home againste any disease, yet not content therewith, they wil seeke for a new farther 
off, and by that meanes many times hurt more than they helpe.” 
Dr. Aveling, in the introductory address to the Sheffield School of Medicine for the 
present session, makes the following confession, which may serve to illustrate the way in 
which reputedly new remedies prove to have been known to our ancestors. He says :— 
“ Nine years since, I published a paper ‘ On the Use of Gentian Tents for Dilating the 
Utei'ine Canal.’ Now, I know that gentian root was much used for dilating canals 
many hundred years since, and that Cooke, in his ‘ Marrow of Chirurgery,’ published in 
1685, actually recommends the use of both gentian and sponge tents when the inner 
orifice of the uterus is closed.” Perhaps the stems of seaweed {Laminaria'), now used as 
dilators, may not be so novel as we suppose. 
Bicarbonate of sodium introduces us to the most important of chemical families, 
when looked at from a technical point of view. The soda manufacture of England is 
the principal element of a group of industries which, in the words of Professor Hof¬ 
mann, “ may be regarded as the foundation of the whole edifice of applied chemistry.” 
The manufacture of sulphuric and hydrochloric acids and hypochlorite of lime is almost 
a necessary sequence to the profitable production of alkali soda. Sulphuric acid plays 
so important a part in the soda manufacture, from its use to convert chloride of sodium 
into sulphate of sodium, that the maker of the alkali usually prepares his own sulphuric 
acid, in order to obtain it at the lowest rate. He is an involuntary producer of hydro- 
