these effects springs from the difference in the subtlety of the medicines themselves. Chloride of mercury (calomel) has been taken from the stomach twenty-four hours after it was administered, in a perfectly unchanged state, and might for that reason have been washed and put back again into the bottle. The fumes of mercury, on the contrary, pervade the system almost instantaneously.

These illustrations will serve to explain the difference between crude medicines and medicinal vapours. Medicated vapours are medicines in their most attenuated and delicate form; they are the minutest possible division of solid and fluid substances; they are the essences separated from the crudity, and their subtlety causes them to act with the rapidity of touch. A grain reduced to vapour is more active than a grain given in substance, and will produce more effect upon the system. It follows, therefore, that, as a rule, small doses in a state of vapour will answer the same purpose that large ones do in the solid state.

Inhalation, then, in the treatment of consumption and chronic affections of the organs of respiration, is the only rational and proper treatment, not only because it is direct, and conveys the medicines to cure, to the part to be cured, but because it conveys them in the form best adapted to prompt action. It may be laid down as an axiom, that medicines act with increased power in proportion to the divisibility of their particles. Inhalation, therefore, not only saves the system from wholesale drugging, by diminishing the doses of medicines, but it saves the healthy organism from injurious action-by limiting their direct influence to the parts which require their aid.

The practice of administering medicines by inhalation is not only based on rational principles, but is in itself an elegant process. It is rational, because it is simple, direct, and natural. It is elegant, because it is free from disagreeable taste to the patient, and does not, like medicines given by the stomach, excite disgust or nausea. No man swallows

drugs in the form of "pills," or "mixtures," or "powders," without a strong effort of the will. He tolerates them when he is sick as a disagreeable necessity. Often, indeed, he neglects his disease, until confirmed, through his aversion to take medicines. INHALATION, ON THE CONTRARY, MAY BE

EMPLOYED BY THE MOST DELICATE AND SENSITIVE INVALID
WITHOUT EXCITING ONE UNPLEASANT FEELING.
THE MOST
POWERFUL MEDICINES CAN IN THIS MANNER BE CONVEYED
INTO THE SYSTEM, AND ALL THEIR BENEFICIAL EFFECTS OB-
TAINED, WITHOUT PRODUCING THE SLIGHTEST DISCOMFORT.

It is to the circumstance of inhaling medicines acting upon the blood and through it on the absorbent system, that we look chiefly for the removal of the tubercular depositions and the final restoration of the lungs to health. I am aware that some physicians speak of inhalation as a "purely local treatment," but such, surely, only manifest their ignorance, not only of the practice of medicine, but also of the physiology of the lungs themselves.

The lungs present an absorbing surface estimated by many physiologists at fifteen hundred square feet, and by none lower than an extent many times exceeding the entire surface of the body. This surface is designed by nature to bring the blood in the most direct manner possible under the purifying influence of the air. Now, that this surface takes up all gaseous substances, whether medicinal or poisonous, contained in the respired air, has been amply proved by every physiologist, and there is no excuse for any physician being ignorant on the subject. For the enlightenment of such as are, I refer them to Professor Carpenter's Human Physiology,' Art. Inhalation and Absorption through the Lungs.' After demonstrating that "the absorption of fluid takes place through the lungs," Dr. Carpenter* passes to the consideration of "volatile matters diffused through the air." the absorption of these he cites many instances:

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Of

*This distinguished man is personally acquainted with cases in which my treatment has proved successful.

"A familiar example," says he, "is the effect of the inhalation of the vapour of turpentine upon the urinary secretion. It can only be in this manner that those gases act upon the system which have a noxious or poisonous effect when mingled in small quantities in the atmosphere; and it is most astonishing to witness the extraordinary increase in potency which many subjects exhibit when they are brought in relation with the blood in the gaseous form."

After giving many illustrations of the promptness and power of inhaled medicines, he closes his observations with the following passage:—

"It cannot be doubted," says he, " that miasmata and other morbific agents diffused through the atmosphere are more readily introduced into the system THROUGH THE PULMONARY surface than by ANY OTHER ! And our aim should therefore be directed to the discovery of some counteracting agents, which can be introduced in the same manner. The pulmonary surface affords a most advantageous chance for the introduction of certain medicines that can be raised in vapour, when it is desired to affect the system with them speedily and powerfully!"

The absorption of particles diffused in the air-their admixture with the blood-and their distribution to all tissues and structures have been clearly demonstrated by frequent experiments of MM. Magendie, Tiedmann, and Liebig, who have detected the odour of camphor, musk, and other remedies, in the blood of animals which had been confined in an atmosphere impregnated with these substances. A certain test is afforded of the iodine vapour producing general effects on the system, by adding to the urine of patients who have thus inhaled it, a few drops of nitrous acid, with a solution of starch, by which a deep blue precipitate is produced, varying in appearance according to the quantity of iodine which has been employed. I have discovered this precipitate after ten minutes' inhalation, which shows how quickly iodine is absorbed into the system. There cannot, indeed, be a reasonable doubt of the doctrine here avowed by Professor Carpenter, that whenever it is desirable to affect the system speedily and powerfully, the medicine, if it can be rendered

volatile, should be inhaled. By availing ourselves of this channel, we are able to overcome the tuberculous condition of the blood, to stay the further formation of tubercles in the lungs, and to promote the absorption and expulsion of those already deposited.

Delpit, in the article "Phthisis Laryngea" in the 'Dictionnaire des Sciences Médicales,' thus concludes: •

"S'il est une espèce de phthisie où les fumigations simples ou composées puissent devenir utiles, c'est sans contredit celle du Larynx, plus accessible à ce genre de remèdes, et par conséquent plus susceptible d'en ressentir l'impression favorable ou funeste. Le phthisique est d'autant plus difficile à traiter, qu'il est devenu susceptible des impressions les plus légères, soit physiques, soit morales; perdant avec la même facilité le repos du corps et le calme de l'âme, il est dans une anxiété continuelle; il désire des alimens, et ceux-ci qui donnent le dévoiement; il veut sortir, et l'exercice le fatigue; il demande des remèdes, et il ne peut les avaler; il boit, et la toux le suffoque; il appele la santé de tous ses vœux, et la mort le mine sourdement. En vain le médecin varie chaque jour ses conseils et ses prescriptions, le terme ou l'objet de l'espérance qu'il donne sans la partager; en vain il laisse entrevoir l'influence de la belle saison, le baume restaurant de la végétation nouvelle, de l'air salutaire des champs; en vain il indique un voyage dans un climat plus chaud, ou vante les effets merveilleux d'une eau minérale, et en promet l'infallible succès; le malade est toujours disposé à recevoir toutes les promesses, à se bercer de toutes les illusions, à s'abandonner à tous les projets; mais la belle saison passe ou arrive, la végétation se ranime ou s'éteint, les feuilles tombent ou poussent; la nature fait éclore les fleurs ou prépare la maturité des fruits, elle dépouille les arbres ou renouvelle leur parure; toutes ces révolutions sont également funestes, et ne servent qu'à marquer le moment où le phthisique descend dans la tombe, occupé de projets et nourri d'illusions."

In the same work, article "Inhalation," by Rullier, are the following remarks, which are important as referring to one of the modes by which we are enabled to account for the beneficial effect produced by the local application of remedies to diseases of the lungs.

"Les vapeurs animales exhalées des chairs et du sang encore chaude des animaux, et mêlées à l'air que nous respirons, ainsi que les émanations des cuisines et des étables, regardées avec raison comme propres à favoriser le bon état de la nutrition chez les bouchers et les cuisiniers, ou à rétablir l'embonpoint de certains malades; l'humidité de l'air atmosphérique, qui diminue le besoin de la soif, et retarde les funestes effects de la faim prolongée, produisent sans doute une partie de ces effets à l'aide de l'absorption des voies aériennes, devenue alors vraiment congénère de l'absorption cutanée.

L'absorption de la membrane muqueuse des voies aériennes est justement regardée comme une cause puissante de la communication de celles des maladies contagieuses dont le principe réside dans l'atmosphère. L'histoire des phénomènes de l'asphyxie par la plupart des gaz délétères, tels que l'hydrogéne sulfuré, le plomb des fosses d'aisances, ou l'hydrosulfure d'ammoniaque, ne permet pas de douter que ce soit moins à l'énergie stupéfiante dont jouissent ces agens sur le système nerveux, qu'à l'absorption réelle qui s'en fait, qu'il faut réellement attribuer l'influence délétère qu'ils exercent sur l'économie."

Since the appearance of the above observations several cases of far-advanced pulmonary consumption, asthma, bronchitis, &c., have been reported in the French medical journals, and more especially in the Journal Hebdomadaire' and the Arch. Gén. de Médecine,' in which complete recovery ensued from the use of medicated inhalations; and this mode of practice is now generally adopted by the most eminent physicians throughout the Continent.

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My lamented friend Dr. Paris, late President of the London College of Physicians, who has left to his country the inheritance of a great name and illustrious reputation, makes the following remarks in the last edition of his celebrated work on Pharmacology under the head of "Inhalations:"

"With respect to this particular form of remedy, it may be observed that, if the power of medicine be so greatly modified by circumstances affecting its solubility, it is fair to infer that the still further diminution of its cohesion may occasion a corresponding influence in its energies; indeed, it would appear that some few substances are entirely inert under any other form. Metallic