OF THE PRINCIPAL POISONS, ORGANIC AND INORGANIC. 
371 
7. Carbonate of Lead. —Residue of yellow oxide. 
8. Morphine. —Melts, darkens, burns like a resin, and deposits carbon. (No 
indication that the poison partially sublimes before melting.) 
9. Strychnine. —Melts, and burns like a resin, with a black, smoky flame. 
(No indication of prior sublimation.) 
10. Aconitine. —Fuses, and burns with a bright yellow flame. 
11. Atropine. —Melts, darkens, and burns with a yellowish smoky flame. 
I will now add an equally short statement of results, described as commonly 
obtained with the reduction-tube, heated by the flame of the spirit-lamp. 
1. Arsenious Acid. —Sublimed without melting, forming a ring of brilliant 
octahedral crystals. 
2. Corrosive Sublimate —Melts, and sublimes as prismatic crystals, sometimes 
stellated. 
3. Oxalic Acid. —Melts; vapour condensed as white crystalline sublimate. 
4. Acetate of Lead. —Melts, becomes solid, melts again, darkens, yielding 
vapours of acetic acid, and leaves residue of carbon and reduced lead. 
5. Tartar Emetic. —Chars, but does not previously melt. Metal partially 
reduced. Residue has a greyish-blue metallic lustre. 
6. Morphine. —As with platinum-foil. Ammonia given off. (No mention of 
any sublimate.) 
7. Strychnine. —Also yields ammonia. (No mention of any sublimate.) 
8. Aconitine. —Evolves vapours, first alkaline, then acid. 
These brief abstracts, taken from a work which is likely to contain as much 
information on this subject as is to be found in any one authority,* will serve to 
show :—1. That two modes of applying heat to poisonous matters are in common 
use, and are deemed to afford indications of such value as to serve, if not as 
tests, at least as necessary elements of their natural history; 2. That these 
methods are either so rough in themselves, or have been used for each poison so 
rarely that some of the phenomena to which they give rise have wholly escaped 
observation ; and 3. That some more delicate and precise mode of applying 
heat is still a great desideratum. 
Now it is obvious that there would be no difficulty in associating with these 
rough methods the determination of the temperature at which the several poi¬ 
sons melt or sublime, and equally obvious that out of such association there 
must inevitably arise such striking differences and contrasts as would serve the 
purposes both of accurate physical history and of diagnosis. It would suffice to 
plunge the bulb of a thermometer indicating high temperatures, and a short 
reduction-tube made of glass of the same thickness as the tube of the thermo¬ 
meter itself, side by side into melting oil, a sand-bath, or even a hollow nipple 
of copper or brass. The melting and subliming temperatures would thus be 
ascertained under the necessary conditions of equality of heat, and the subli¬ 
mates would form in the higher part of the tube. If the tube were made of the 
glass which presents in section a flattened ellipse, and it were drawn out into a 
capillary tube, it would be easy to seal the capillary portion at both ends, and 
examine the contents under the microscope. 
But as, by adopting this plan, we should sacrifice the great advantages which 
obviously arise from substituting a flat surface of glass for the reduction-tube, I 
did not hesitate to prefer an arrangement which would enable me to ascertain 
the melting or subliming temperature, or both, with sufficient accuracy for 
every practical purpose, at the same time that I retained the advantage of the 
glass disk. The simple apparatus which I devised for this purpose, and which 
I found to admit of ready application, and to yield very satisfactory results, is 
* ‘The Principles and Practice of Medical Jurisprudence,’ by Alfred Swaine Taylor, M.D., 
F.R.S., etc. 
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