was small, yet it was sufficient, by the aid of the sun of last October, to produce steam enough to keep a sewing-machine in continuous motion, cook food, and boil water. M. Mouchot's machine consists of a reflector in the form of a truncated cone, which concentrates the rays of the sun upon a kettle placed in the axis of the cone, with a bell glass to cover the kettle and protect it from external cooling. Such machines are not likely to be of much practical use in temperate climates, where the sun is comparatively weak and often clouded; but in hot, arid regions, like the deserts of Africa, they may possibly yet be employed advantageously.
Consumption and Climates.—Dr John C. Thorowgood, of the London Hospital for Diseases of the Chest, in a paper on "Atmospheric and Climatic Influence in the Causation and Cure of Pulmonary Disease," distinguishes between two classes of phthisis, or consumption of the lungs, in which the operation of this influence is very different. The first kind, the consumption which originates in catarrh, cold, or some inflammatory attack, prevails in raw, cold climates, and is relieved by going to a mild climate. The second kind, true tubercular consumption, comes on insidiously, often from no cold caught, from no privation of food, but simply from some inherent, perhaps hereditary vice in the system, and is a febrile disease, having much the character of rapid blood-poisoning. It is not peculiar to cold climates, and is not relieved by sending the patient to a mild one. The worst that can be done in cases of either form of disease is, to confine the patient closely to one room, and let him breathe over and over again the same atmosphere, while the cough is kept checked by opiates. In this way, says Dr. Thorowgood, consumption may be cultivated and developed from the first class into the more serious form of the second class, so that it becomes a fearfully destructive malady. "In the cases of young children who are kept very close in heated rooms, and who are said to be always taking cold, we often see most obstinate cough and catarrh, due to the throwing off from the air-passages of a weak, poorly-nourished epithelium, which in time may choke the air-cells, and so lead to pulmonary consumption. The cure consists in laying aside paregoric and squills while we feed the epithelium with pure air. Appetite soon returns, and the cough speedily takes its flight." The tendency of confinement in a close atmosphere to cause blood-spitting and consumption has been demonstrated by the statistics obtained by Dr. Gray when engaged in investigating the effects of certain trades on the health of those employed. The author of the paper under notice has seen excellent results, in removing lingering inflammation after an acute attack on the chest, follow a sojourn at Torquay, Ventnor, and similar mild, warm health-resorts; but when the disorder has passed from the inflammatory stage to one that involves the general nutrition, and is marked by softening and breaking down of lung-tissue, with night-sweats and copious purulent expectoration, he has never seen any good come of a residence in a mild, sedative climate. On the other hand, he tells of several cases in which persons suffering from the latter form have been relieved, and have even recovered after being sent to a cold, bracing climate, or to a high mountain elevation. The author's views were confirmed, in the discussion by the medical society before which it was read, by several speakers. The president of the society mentioned three cases of complete cure of decided pulmonary consumption of non-catarrhal origin by change of air—in one case to Moscow, in two others to Canada. Another speaker mentioned cases of catarrhal phthisis that had been cured by sojourn at mild resorts.
Effect of Physical Training on Respiration.—M. Marey has made an investigation of the modifications which are induced in the respiratory movements by the fact of muscular action. It is well known that muscular action provokes, in those who are not accustomed to it, panting, that is, a respiration stronger and more frequent than the normal respiration. This is in consequence of the greater rapidity of the current of blood which in its abundance demands, in order to pass through the lungs, more frequent or more ample respirations. The habit of muscular exercise, running, for example, has the effect of gradually adapting the respiratory function to the most rapid cir-
