Fumigation with carbolic acid is an undoubted cure, but then it is a dangerous one, and unless very great care is taken in killing the worms, the bird is killed also. Thus many find this a risky method, and prefer some other. Lime is found to be a valuable remedy. In some districts of England, where lime-kilns abound, it is a common thing to take children troubled with whooping-cough there. Standing in the smoke arising from the kilns, they are compelled to breathe it. This dislodges the phlegm in the throat, and they are enabled to get rid of it. Except near lime-kilns, this cannot be done to chickens, but fine slaked lime can be used, either alone or mixed with powdered sulphur, two parts of the former to one of the latter. The air is charged with this fine powder, and the birds, breathing it, cough, and thus get rid of the worms, which are stupefied by the lime, and do not retain so firm a hold on the throat. An apparatus has recently been introduced to spread this lime powder. It is in the form of an air-fan, with a pointed nozzle, which is put just within the coop at night, when the birds are all within. The powder is already in a compartment made for it, and by the turning of a handle, it is driven through the nozzle, and the air within the coop charged with it. There is no waste of powder, nor any fear that it will not be properly distributed. Experienced pheasant and poultry breeders state that by the use of this once a week, gapes are effectually prevented. In this case, also, I shall be glad to learn the result if tried. STEPHEN BEALE. H----, Eng., Aug. 1. --_Country Gentleman_. * * * * * WOLPERT'S METHOD OF ESTIMATING THE AMOUNT OF CARBONIC ACID IN THE AIR. There is a large number of processes and apparatus for estimating the amount of carbonic acid in the air. Some of them, such as those of Regnault, Reiset, the Montsouris observers (Fig. 1), and Brand, are accurate analytical instruments, and consequently quite delicate, and not easily manipulated by hygienists of middling experience. Others are less complicated, and also less exact, but still require quite a troublesome manipulation--such, for example, as the process of Pettenkofer, as modified by Fodor, that of Hesse, etc. [Illustration: APPARATUS FOR ESTIMATING THE CARBONIC ACID OF THE AIR. FIG. 1.--Montsouris Apparatus. FIG. 2.--Smith's Minimetric Apparatus. FIG. 3.--Bertin-Sans Apparatus. FIG. 4.--Bubbling Glass. FIG. 5.--Pipette. FIG. 6.--Arrangement of the U-shaped Tube. FIG. 7.--Wolpert's Apparatus.] Hygienists have for some years striven to obtain some very simple apparatus (rather as an indicator than an analytical instrument) that should permit it to be quickly ascertained whether the degree of impurity of a place was incompatible with health, and in what proportion it was so. It is from such efforts that have resulted the processes of Messrs. Smith. Lunge, Bertin-Sans, and the apparatus of Prof. Wolpert (Fig. 7).