a species of consumption, occasioned by an ulcer in the lungs. See MEDICINE, no. 237, &c.

Since our article MEDICINE was published, Dr Beddoes has suggested a new theory of phthisis, founded on the prevailing pneumatic doctrine in chemistry. Thinking that much cannot be gained by adhering to established principles and modes of practice, and being unmoved by any pretensions to success from experience, surgery, &c., he enters into the province of speculation. He fixes on the effect of pregnancy in suspending the progress of phthisis, as a fact which, by its mode of operation, might might suggest a method of diminishing the havoc occasioned by this distemper. We shall give his explanation of this interesting fact:

"The fetus has its blood oxygenated by the blood of the mother through the placenta. During pregnancy there seems to be no provision for the reception of an unusual quantity of oxygen. On the contrary, in consequence of the impeded action of the diaphragm, less and less should be continually taken in by the lungs. If, therefore, a somewhat diminished proportion of oxygen be the effect of pregnancy, may not this be the way in which it arrests the progress of phthisis? and if so, is there not an excess of oxygen in the system of consumptive persons? and may we not, by pursuing this idea, discover a cure for this fatal disorder?"

Dr Beddoes thinks, that this supposition is countenanced by the deficiency of oxygen in the blood of pregnant women, of asthmatic patients, and of those who labour under sea-fever; and by the superabundance of it in the blood of phthisical persons, indicated by its colour, as well as by the aggravation of the symptoms of consumption by breathing oxygen air, and by the relief from inspiring atmospheric air mixed with carbonic acid air; and, lastly, from the small proportion of deaths among sea-faring people. Supposing acids to act by decomposition, their alleged effects in producing consumption are consistent with the author's doctrine, as well as the emaciation preceding and accompanying phthisis. From these facts, Dr Beddoes concludes, that "1. The phthisical inflammation may so alter the structure of the lungs, as to cause them to transmit a more than ordinary portion of oxygen to the blood; or, 2. Some unknown cause having enabled them to transmit, or the blood itself to attract, more oxygen, an inflammation of the lungs might ensue."

From these principles, the Doctor thinks himself justified in proposing, in a disease which is incurable by present modes of practice, to diminish the supply of oxygen by the two channels through which it is introduced; namely, through the lungs, by lowering the atmospheric air with azotic or hydrogenic air; and through the stomach, by giving such nourishment as contains only a small portion of oxygen.

Such is Dr Beddoes's theory of consumption; on which the following remark has been made by a critic* who possesses an equal degree of candour and judgment. It is affirmed by Dr Beddoes, that the blood of pregnant women has a diminished proportion of oxygen; but pregnant women have the same circumcised spot of florid red in their countenances which is apparent in hectic. If, then, the presence of this colour be sufficient to prove an excess of oxygen in the one case, it must have the same weight in the other. Another question is, whether less oxygen be really taken in by the lungs during pregnancy? For although the diaphragm be impeded in the freedom of its action, the frequency of breathing is proportionally increased.—A third circumstance which demands attention is, in what degree the fetus has its blood oxygenated by the blood of the mother through the placenta. It appears highly probable, that the fetal blood receives a very trifling supply of oxygen from the blood of the mother; that the fetal heart contains only a small portion of blood, which has been conveyed to the placenta; and that the blood in the heart and arteries of the fetus is not florid.—For many ingenious arguments on this subject, we may refer to Mr Coleman's Dissertation on suspended Respiration.—Leaving these things to Dr Beddoes's consideration, we will present our readers with his concluding remarks on this subject:

"The more you reflect, the more you will be convinced, that nothing would so much contribute to rescue the art of medicine from its present helpless condition, as the discovery of the means of regulating the constitution of the atmosphere. It would be no less desirable to have a convenient method of reducing the oxygen to 18 or 20 in 100, than of increasing it in any proportion. The influence of the air we breathe is as wide as the diffusion of the blood. The minutest portions of the organs of motion, sense, and thought, must be affected by any considerable change in this fluid. Whether it be that the brain must be washed by streams of arterial blood, or that the action of every organ is a stimulus to the system in general, and consequently to every other organ in particular; it is certain, that when the access of oxygen is cut off from the lungs, the functions of the brain cease: perhaps there may be a mixture of azotic and oxygen airs, more favourable to the intellectual faculties than that which is found in the atmosphere; and hence chemistry be enabled to exalt the powers of future poets and philosophers. That diseases of excitement on the one hand, and debility on the other, might be cured almost solely by a proper air, one can hardly doubt, as well as several disorders at present highly dangerous or desperate, which one cannot, upon the faith of any obvious phenomena, refer to either head. The materia medica might, therefore, undergo a still greater reduction than it has lately undergone, in consequence of the purification of medicine from its grosser absurdities; and hence the treatment of diseases be at once rendered infinitely more pleasant and more efficacious."

Our author, in a subsequent publication*, gives an account of his treating with success several cases of phthisis according to the principles of this theory. After distinguishing consumptions into two kinds, the florid and the pituitous or catarrhal, he observes, "that the system may be as variously affected by means of the lungs as of the stomach: that it is impossible to doubt that we are nourished by the lungs as truly as by the stomach: and that what we take in at the former entrance, becomes, like our food, a part of the substance of our solids as well as of our fluids. By the lungs we can also introduce effectual alternatives of the blood, and by consequence of all the parts nourished by the blood."

He then acquaints us more particularly with the apparatus requisite for the practice proposed. If, it should be able to furnish azotic, hydrogenic, carbonic, and oxygenic airs: our author having, as he says, "no intention to confine himself to one incurable disorder." The reservoirs should be large, that the patients may be supplied with any quantity that their symptoms may require: and, finally, it is necessary to be able to mix these airs with one another, as well as with atmospheric air, in any proportion." These objects, we