TRANSACTIONS OF THE SECTIONS. 47 
lents. In alloys of copper with tin, it was found that where only a small quantity of 
tin entered into the composition of a bar, the expansion fell considerably below that 
of pure copper, although the tin thus added has a much higher ratio of expansion 
than copper. 
The following is one of the Tables accompanying the paper. 
Coefficient of Expansion from 0° to 100°. 
Cadmium ...,.,,....+++.+- 0°003323 | Copper (hammered) ,...,.., 0°001769 
Ne eps wate asics ee 0°003005 | Gold (GOP RAC REE . 0°001374 
et a steal arate /auaisiaia + Pam OOA Liga RISIOUEH (COs )o s osa$: ate « ote . 0°001341 
Aluminium,......... Kala Gsw alk 0°002218 | Iron (forged) .,..... jaete ea Ol Lar 
Zinc (hammered) ........ -- 0°002193 | Castiron ....eeseeesevees 07001117 
Silver (cast). ....s0ce0%s e000, 0001991, Steel (hard) ..)...eeecesese 0001402 
BIPORE (GQ:) os cc cy vcasasouse. 0 001930 | Steel (Soft), ..neseerrerxee 0°001088 
Copper (do.) ......+++2+++» 0°001879 | Antimony (cast),......,..., 0°000985 
Brass (hammered) .......... 0°001828 | Platinum (forged) ,.,....,.., 0°000881 
Note on Nitro-glycerine and other Xyloids. By J. Baker Epwarps, Ph.D., 
Lecturer on Chemistry and Toxicology, Royal Infirmary School of Medi- 
cine, Liverpool. 
The author stated that he had made a considerable number of experiments upon 
various animals to ascertain the physiological effects of these substances, some of 
which he found possessed poisonous properties. 
Dr. De Vry introduced the substance known as nitro-glycerine or glonoine, to the 
notice of the British Association at Ipswich, and observed that from some experiments 
made upon rabbits, he concluded that it was not a poison. The experiments of Mr. 
Field, however, showed that it possesses a powerful physiological action upon man; 
and the author had in a great number of instances observed and experienced violent 
and protracted headache and irregularity of the heart’s action follow the administra- 
tion of a single drop; upon animals, viz. frogs, birds, rabbits, and cats, doses of from 
four to ten drops produce at first similar symptoms and dilation of the pupil of the eye. 
After apparent recovery from these first effects, a secondary chain of symptoms set in, 
viz. vertigo, trismus, violent tetanic convulsions, lasting in some cases for three or 
four hours, and then terminating in death by exhaustion. Shortly before death, ex- 
treme contraction of the pupil of the eye is observed, and the animal becomes stupe- 
fied and nearly unconscious; when the animal is disturbed, however, a convulsive 
paroxysm takes place, resembling that produced by strychnine. 
Similar experiments were made upon xyloidine from sugar, washed until all bitter- 
ness was removed. No effects were produced. 
Upon xyloidine from starch, which produced convulsions in the rabbits; but no 
fatal effects were produced in a quantity of ten grains. 
Upon pyroxyline collodion, which produced no marked effect. 
lt is possible in the latter case the ether is antidotal to the peculiar action of xyloi- 
dine, for when administered to persons suffering from the effects of glonoine it affords 
prompt relief. The author had not concluded his experiments upon this subject. 
A Process for the Estimation of Actinism. By R. J. Fow.Er. 
In the ninth volume of Gmelin’s ‘ Handbook of Chemistry,’ we find it stated that 
* oxalate of ammonia mixed with aqueous protochloride of mercury is decomposed 
under the influence of light, yielding sal-ammoniac, calomel, and carbonic acid ;” it 
is also stated that “‘ the mixture of the two solutions remains clear in the dark, in 
daylight it becomes turbid in six minutes, and in the course of an hour deposits calo- 
mel, which in sunshine quickly falls down in soft flakes surrounded with bubbles of 
carbonic acid. The filtrate no longer contains mercury, but chloride of ammonium and 
undecomposed oxalate of ammonia.” 
On seeing this, the author conceived that here might be the elements of a process 
for actinometry ; the following’ ate the results of experiments which he has tried on 
the subject. 
It is perfectly correct that the two solutions named may be kept mixed unchanged 
