various parts, will be understood from the two drawings, and especially from the lettered section with descriptive notes. This form of the apparatus has been thoroughly tested by Dr. Thoinot, of Paris, who came to the conclusion that it "surpassed other disinfectors then used in the French hospitals."

Reck's disinfector, with separate drying arrangement, was shown at the exhibition connected with the Sanitary Institute Congress held in Liverpool in the autumn of 1894, and, on the author's suggestion, the inventor kindly had the apparatus (the cylindrical form measuring 7 feet by 3 feet) fixed in Stafford after the closure of the exhibition to allow of its power being tested. In these trials the author had the advantage of the valuable help of Drs. Whitelegge* and Barwise, the County Medical Officers of West Riding of Yorkshire and Derbyshire, and Dr. Blumer, the Medical Officer of Health of Stafford.

The special features of the apparatus, with separate drying arrangement, are-(a) the use of low-pressure steam, delivered to the apparatus by an automatic regulator at a rate which cannot be exceeded, (b) the absence of any steam jacket, and (c) an arrangement by which a cold water shower can be turned into the chamber with the object of rapidly removing all steam from the interior after the process of disinfection is completed. As regards the cold shower, it is introduced at the top of the apparatus and falls on to an umbrella spread in the upper part of the hot chamber which distributes the stream over a large surface and conducts the water to the lower part of the apparatus, where it escapes in such a manner that it does not come in contact with the articles which are being disinfected. The result of the sudden introduction of the cold shower is a rapid cooling and the condensation of all live steam in the chamber, this steam being automatically replaced by air entering through a valve in the front of the apparatus as fast as the steam is condensed by the cold water.

In the experimental trials the pressure employed did not exceed 1 lbs., and they were conducted with the view of ascertaining: (1) the penetrating power of the low-pressure steam, and the temperatures obtained in various thicknesses of clothing; (2) the degree of moisture remaining in the articles after the process; and (3) the destructive power of the apparatus as regards organisms.

By means of an electric thermometer, set to ring at 212° F., and recording maximum thermometers placed between various folds of blankets, &c., the rapidity of penetration, and the temperatures under different conditions as regards resistance were ascertained. The amount of moisture remaining in the articles was estimated by weighing them before and after the process. * Now H.M. Chief Inspector of Factories.

As regards the efficiency of the apparatus, its power of destroying various bacteria, suspended in the chamber and placed in folded blankets and between mattresses, was ascertained by cultivation experiments.

The following table shows the temperature attained under various conditions:

As regards the rapidity of penetration, it may be considered highly satisfactory, for it probably does not often happen in actual experience that greater resistance than is represented by 16 folds of woollen material will have to be overcome, and that the results recorded in the table can be attained by the Reck apparatus was demonstrated by a series of tests. To place the thermometer between two thick flock mattresses is a very severe test, and it speaks well for the apparatus that in 35 minutes after the introduction of the steam a temperature within 1 degree of boiling point was recorded. It is interesting to note that the temperature in the cavity of the chamber was over 4 degrees lower than the recorded temperature within 16 folds of blankets -a circumstance which may possibly be accounted for by the liberation of latent heat owing to condensation in the interstices of the material.

As regards the dryness of the blankets at the end of the process, the following are the results with and without using the cold water shower :

1

2

3

4*

5

6

7*

* In the fourth and seventh experiments the blankets were hung loosely

in the apparatus; in the others they were folded compactly.

Taking the means of these figures, and expressing the degrees of dampness by the percentage increase of weight in each case the following results are arrived at :—

It would seem then that the cold shower does not assist in the drying process, nor is it claimed for it that it does, but it has a very marked effect in condensing the steam in the apparatus ; without it volumes of steam escaped on opening the door, whereas, with it little or no steam was perceptible. That the shaking process is less effectual in removing moisture in the case of blankets loosely suspended in the apparatus is no doubt explained by the fact that the heat is largely retained in blankets which are folded up, and when they are suddenly shaken in the air evaporation would naturally be more active than it would in the case of blankets which, owing to the large surface exposed, had cooled considerably before the shaking while being removed from the apparatus.

As regards the bacteriological tests, which Dr. Barwise kindly conducted, anthrax bacilli and spores, garden soil, and human excreta were used, and, with the exception of a few soil bacteria, which are known to be highly tenacious of life and which survived the process, this part of the experiment was entirely successful, as was proved by control experiments in every case. The bacteria, as already mentioned, were placed free in the chamber, as well as within 16 folds of blankets, and between two flock mattresses, and subjected to the prescribed routine of treatment, and in no instance, with the above exception, did any growth take place on gelatine in the case of the disinfected specimens, while in every instance duplicate specimens which had not been treated in the apparatus freely germinated on gelatine plates.

To sum up then, the experiments seem to warrant the conclusion that in Reck's disinfector we have a very efficient apparatus capable of destroying the ordinary pathogenic microbes.

The cost of an apparatus similar to the one experimented with,

including the drying chamber complete and all necessary appliances, amounts to £77, very much less than other equally efficient apparatus hitherto used in this country. Probably a smaller apparatus would answer the requirements of public institutions and smaller districts, in which case, of course, the cost would be less.

An adaptation of Reck's apparatus is made in portable form and of a size corresponding with the one experimented with at Stafford-perhaps the most useful size for general use. The weight of this portable apparatus is just over 27 cwts., and it costs £180. When the provision of disinfecting apparatus becomes more general, and rural as well as urban Sanitary Authorities come to look upon such appliances as being essential to the efficient control of infectious disease, the probability is that the portable form will be more generally used.

Thresh's disinfector, designed by Dr. Thresh, County Medical Officer, Essex, is a current steam apparatus by means of which a temperature exceeding 212° F. is obtained without employing pressure. This is accomplished by using for the generation of the steam a saline solution which boils at a higher temperature than water. The apparatus is simple, ingenious, and efficient, and it costs very much less than others in which high-pressure steam is used.

The following drawing (Fig. 105), showing a section of the apparatus, will enable the reader to understand its construction. It will be noticed that the chamber in this case has only one door, but the apparatus is also made with two doors, one communicating with a room where the infected articles are introduced, and the other with an entirely distinct room, where the articles are removed on the completion of the process of disinfection. The principle of construction, however, in both cases is the same.

The disinfecting chamber, A, is surrounded by a jacket, B, containing the saline solution, which is maintained at a certain level, and renewed as evaporation takes place by means of a water pipe, L, connected with a ball-tap cistern, I, fixed outside the apparatus. The furnace, K, for heating the saline solution is constructed underneath the chamber, and the steam which is thus generated in the upper part of the jacket can be directed by means of a valve, G, either into the chimney of the furnace, or downwards to a coil of pipes, E, laid in the solution at the bottom of the jacket, through which it circulates before entering the chamber at the point, C. Passing from the upper part of the chamber to the furnace flue is a pipe, D, which allows the steam to escape from the interior of the chamber.