366 
THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. [November 5,1870. 
lents of potassium, sodium and lithium are, respectively, 
39-1, 23 and 7. Now, 23 is the exact arithmetical mean 
between 39 and 7; and in energy and general resem¬ 
blance sodium is the mean of potassium and lithium. 
The equivalents of the members of the chlorine group 
exhibit a somewhat similar relationship, only not so pre¬ 
cisely. They are 35-5, 80 - 0 and 127’0, the middle one 
not being quite the arithmetical mean. Barium, stron¬ 
tium and calcium afford a similar example, viz. 68*5, 43 
and 20 respectively. In the potassium group the highest 
equivalent and highest energy go together; in the chlo¬ 
rine group the least equivalent is joined to the highest 
energy (chlorine being more energetic than bromine, and 
bromine more energetic than iodine); in the barium 
group the order is curious, viz. highest equivalent with 
highest energy (barium); next, intermediate equivalent 
with lowest energy (strontium); and last, lowest equi¬ 
valent with intermediate energy (calcium). 
A suggestive relationship subsists between the equiva¬ 
lents of oxygen and sulphur, chemical fellows with 
strongly-marked resemblances, whose equivalents bear 
to one another the exact ratio of 1 to 2. 
Lastly, nickel and cobalt offer a marvellous case of re¬ 
semblance. Chemically, they are almost indistinguish- 
•ably alike in their compounds; physically, they are like 
•one another as isolated elements; and their equivalents 
are absolutely identical, so far as the most accurate de¬ 
terminations have been able to show. 
Postal Cards and Sympathetic Ink. —The in¬ 
troduction of the halfpenny postal-cards, with the direc¬ 
tion on one side and the correspondence on the other, has 
given interest to the subject of sympathetic ink. One of 
the best-known kinds of sympathetic ink consists of a 
weak solution of chloride or nitrate of cobalt. Writing 
executed with such a solution is invisible until it is 
warmed, when it appears green or bluish, disappearing 
on exposure to moist air; the explanation being, that 
the anhydrous chloride and nitrate of cobalt are deep 
green or bluish, whilst the hydrated salts are very pale 
pink—invisible in small quantities of salt. If, instead of 
chloride or nitrate, acetate of cobalt containing a little 
nitre be used, then the writing will come out in pale rose- 
coloured characters, visible whilst warm and invisible 
when cold. Another variety of sympathetic ink consists 
of weak infusion of galls. To render the writing visible, 
it must be dipped into solution of an iron-salt, the com¬ 
mon sulphate or green vitriol answering the purpose very 
well. Yellow prussiate of potash, dissolved in water, 
also makes an ink which becomes visible on treatment 
with persalts of iron. A great number of possible solu¬ 
tions will at once suggest themselves to the chemist; 
thus the writing might be done with acetate of lead and 
rendered visible by means of a solution of sulphuretted hy¬ 
drogen. No doubt basic acetate of lead would be superior 
to neutral acetate for such a purpose. Most, and possibly 
all, kinds of sympathetic ink give writing which becomes 
more or less visible when the paper written upon is very 
strongly heated, to the point of becoming slightly burnt. 
Some of the solutions which are sometimes recommended 
as sympathetic ink, as, for instance, solutions of silver 
and gold, are very unsatisfactory, becoming visible on 
exposure to the light. Hence, many sympathetic inks 
are little to be relied on, and the safest are those, such as 
the basic acetate of lead, which require a special solu¬ 
tion for their development.— British Medical Journal. 
Explosion of Naphtha. —On Wednesday evening, 
Oct. 26, while a party of men onboard H.M.S. Hercules 
were lowering a cask containing Hay’s Patent Anti- 
Fouling Composition into the carpenter’s store-room, it 
fell from the slings, and bursting, its contents ran over 
the deck. Some men were sent to clean the deck, who 
took with them two lamps. The vapour of the naphtha 
used in the composition coming in contact with the 
lights caused an explosion, which was followed imme¬ 
diately by a second, the flame on each occasion rising 
through the hatchway to the upper deck. Upon descend¬ 
ing into the storeroom, where the effluvium was most 
overpowering, it was found that six men were severely, 
and three slightly, burned. As a quantity of the liquid 
had reached the “ double bottom” under the store, both 
compartments were, as soon as possible, flooded with 
water, to prevent the possibility of a fire breaking out.— 
Standard. 
Poison of Acorns. —Sir George S. Jenkinson has 
written a letter to the Times , stating that in the neigh¬ 
bourhood of his seat at Eastwood Park, Berkeley, 
Gloucestershire, the cattle are dying by scores from 
having eaten too many acoms which had fallen during 
the late gale. If once a beast is taken ill nothing seems 
to have any effect on the inflammation which ensues, 
death following more or less quickly in each case. The 
poison affects the intestines, blackening and rotting 
away the mucous membrane. He says that it is only 
the cattle that have been out and eaten largely of the 
acoms that are affected. 
Preserved Meat. —It is well known that meat pre¬ 
served in tins by the ordinary process of heating in a 
chloride of calcium bath for a prolonged period and 
then closing the orifice, is surrounded by jelly, which, 
with most of its juice, has been extracted from the meat, 
leaving a tasteless and exhausted fibre. To obviate 
this objection a method has been adopted by Mr. Richard 
Jones, in which the steam is exhausted from each tin by 
a tube connected with a vacuum chamber, the meat 
being thus dried with its juices left in their natural place 
amongst the muscular substance, while the whole pro¬ 
cess can be effected at a lower temperature, and with 
less injury to the flavour and appearance of the meat. 
Bocal Applications to Burns. —Dr. A. D. Bin- 
kerd, writing in the Philadelphia Medical and Surgical 
Reporter (July 9th, 1870), prefers, as an application to 
bums when first seen, carbolic acid and glycerine, in the 
proportion of from 5 to 10 drops of the former thoroughly 
incorporated with 2 ounces of the latter, spread on with 
a camel’s-hair or other light brush, then a layer of raw 
cotton, over which a roller-bandage is neatly adjusted. 
For the suppuration following bums he recommends the 
following dressing:—Yellow wax, melted and strained, 
£i; raw linseed-oil ^iij > tannin 5i; subnitrate of bis¬ 
muth, gr. xx. The wax must be first melted, the oil 
then added, and the whole stirred until incorporated; 
next, the tannin is added, and lastly the bismuth. The 
ointment should be applied on pieces of lint. 
Adulteration of Catechu. —It is a well-known fact 
that catechu is often adulterated; the sophisticated sub¬ 
stance injuriously affecting various operations in which 
it is employed, especially dyeing and calico-printing. 
According to Tissandier, genuine catechu, when ex¬ 
hausted by means of ether, loses 53 per cent, of weight, 
leaving, after drying, 47 per cent, of residue. A mixture 
of catechu and alum gives a white precipitate with nitric 
acid and with chloride of barium. 
Solvent for the Ear Wax. —After a series of 
experiments made by Dr. Petrequin, of Lyons, in which 
he tried successively olive oil, glycerine and oil, alcohol 
and olive oil, olive oil and oil of turpentine, ether, alka¬ 
line solutions, soap and water, chloroform, sulphuret of 
carbon, etc., he has arrived at the conclusion that the 
old remedy of tepid water is the best for the purpose. 
Antidote to Carbolic Acid. —Sweet oil or castor 
oil swallowed in large quantities are recommended as the 
most efficient antidotes to carbolic acid, when it has been 
taken in poisonous doses. 
New Application of Chloral Hydrate. —A wntei 
in the Lancet reports that he has used chloral hydrate 
combined with chloric ether successfully in severe cases 
of diarrhoea. 
