3. In the slower cases there were regular fits of violent tetanus; but in the very rapid cases the animals perished just as the fit began to show itself with retraction of the head. When an animal is poisoned with a dose not quite sufficient to cause death, it is seized in 1 or 2 m. with giddiness, weakness, and salivation, then with tetanic convulsions, and at last with gradually increasing insensibility. After lying in this state for some time the insensibility goes off rapidly, and is succeeded by a few attacks of convulsions and transient giddiness. The whole duration of such cases of poisoning sometimes does not exceed half an hour, but may extend to a whole day or more. (Ibid.)
4. The external phenomena due to the action of prussic acid are especially centered, in all warm-blooded animals, in disturbances of the respiratory movements; these are either more or less quickly abolished, or are excessively retarded. As a rule, the typical poisoning case commences with ten or twelve unusually hurried respirations, which are immediately succeeded by an attack of tetanic convulsions, during which the diaphragm remains contracted and immovable. Should the animal not die, as it generally does, in this attack, then all the muscles become relaxed, and deep breathing succeeds with very short inspirations, strikingly long expirations, and unusually long intervals between the individual breaths. If the animal recovers, these respiratory pauses gradually give way to more natural breathing; but if it does not recover, death ends the scene in less than an hour, without any fresh convulsive attack. The blood-pressure and pulse-frequency, after being slightly increased for a few seconds by prussic acid, become considerably lessened. But it is by no means easy to kill the heart by doses of prussic acid. If death by asphyxia be hindered by artificial respiration, even when enormous doses of the acid were given, the heart beat regularly, though rather slowly, until the animals finally recovered from the poisoning. (BOEHM, Ziemssen’s Cyclop., vol. xvii.)
5. The spinal cord of a dog was divided between the last dorsal and first lumbar vertebrae, so that the hind legs were completely paralysed and insensible to mechanical irritants. H. acid was then introduced into one of the hind legs; in one morning symptoms of poisoning commenced; the hind as well the fore legs were violently convulsed, and in twelve morning the animal was dead. (Wedemeyer, in Pereira.).
Hughes was a great writer and a scholar. He actively cooperated with Dr. T.F. Allen to compile his 'Encyclopedia' and rendered immeasurable aid to Dr. Dudgeon in translating Hahnemann's 'Materia Medica Pura' into English. In 1889 he was appointed an Editor of the 'British Homoeopathic Journal' and continued in that capacity until his demise. In 1876, Dr. Hughes was appointed as the Permanent Secretary of the Organization of the International Congress of Homoeopathy Physicians in Philadelphia. He also presided over the International Congress in London.