Much attention has been paid in recent times to disinfecting agents, and among these sulphurous acid and sulphide of carbon must be placed in the list of the most efficient. Mr. Alf. Riche has recently summed up in the Journal de Pharmacie et de Chimie the state of the question as regards these two agents, and we in turn shall furnish a few data on the subject in taking the above named scientist as a guide.
Mr. Dujardin Beaumetz some time ago asked Messrs. Pasteur and Roux's aid in making some new experiments on the question, and has made known the result of these to the Academy of Medicine. At the Cochin Hospital he selected two rooms of 3,530 cubic feet capacity located in wooden sheds. The walls of these rooms, which were formed of boards, allowed the air to enter through numerous chinks, although care had been taken to close the largest of these with paper. In each of the rooms were placed a bed, different pieces of furniture, and fabrics of various colors. Bromine, chlorine and sulphate of nitrosyle were successively rejected. Three sources of sulphurous acid were then experimented with, viz., the burning of sulphur, liquefied sulphurous acid, and the burning of sulphide of carbon. The rooms were closed for twenty-four hours, and tubes containing different proto-organisms, and particularly the comma bacillus made known by Koch, were placed therein, along with other tubes containing vaccine lymph.
After each experiment these tubes were carried to Mr. Pasteur's laboratory and compared with others.
FIG. 1. - BURNER FOR SULPHUR.
The process by combustion of sulphur is the simplest and cheapest. To effect such combustion, it suffices to place a piece of iron plate upon the floor of the room, and on this to place bricks connected with sand, or, what is better, to use a small refractory clay furnace (as advised by Mr. Pasteur), of oblong form, 8 inches in width by 10 in length, and having small apertures in the sides in order to quicken combustion.
In order to obtain a complete combustion of the flowers of sulphur, it is necessary to see to it that the burning is effected equally over its entire surface, this being easily brought about by moistening the sulphur with alcohol and then setting fire to the latter. Through the use of this process a complete and absolute combustion has been obtained of much as from 18 to 20 grains of sulphur per cubic foot.
In the proportion of 8 grains to the cubic foot, all the different culture broths under experiment were sterilized save the one containing the bacteria of charbon. As for the vaccine virus, its properties were destroyed. This economical process presents but two inconveniences, viz., the possibility of fire when the furnace is badly constructed, and the alteration of such metallic objects as may be in the room. In fact, the combustion of sulphur is attended with the projection of a few particles of the substance, which form a layer of metallic sulphide upon copper or iron objects.
FIG. 2. - CKIANDI BEY'S APPARATUS FOR BURNING CARBON SULPHIDE.
The use of liquid sulphurous acid in siphons does not offer the same inconveniences. These siphons contain about one and a half pounds of sulphurous acid. The proportion necessary to effect the sterilization of the culture broths is one siphon per 706 cubic feet. In such a case the modus operandi is as follows: In the middle of the room is placed a vessel, which is connected with the exterior by means a rubber tube that passes through a hole in the door. After the door has been closed, it is only necessary to place the nozzle of the siphon in the rubber tube, and to press upon the lever of the siphon valve, to cause the liquid to pass from the siphon to the interior of the vessel. The evaporation of the liquid sulphurous acid proceeds very rapidly in the free air. This process is an exceedingly convenient one; it does away with danger from fire, and it leaves the gildings and metallic objects that chance to be in the room absolutely intact. Finally, the acid's power of penetration appears to be still greater than that which is obtained by the combustion of sulphur. It has but one drawback, and that is its high price. Each siphon is sold to the public at the price of one dollar.
To municipalities using sulphurous acid in this form the price would be reduced to just one-half that figure.
It will be seen, then, that for a room of 3,530 cubic feet capacity the cost would be $5.00 or $2.50.
The combustion of sulphide of carbon furnishes an abundance of sulphurous acid, but has hitherto been attended with danger. This, however, has recently been overcome by the invention of a new burner by Mr. Ckiandi Bey. The general arrangement of this new apparatus is shown in Figs. 2 and 3.
Mr. Ckiandi's burner consists of an external vessel, A B C D. of tinned copper, containing a vessel, I H E F, to the sides of which are fixed three siphons, R, S.
FIG. 3. - SECTION OF THE APPARATUS.
To operate the burner, we place the cylindrical tube, K L M N, in the inner vessel, and pour sulphide of carbon into it up to the level aa. This done, we fill the external vessel with water up to the level bb. Thanks to the siphons, the water enters the inner vessel, presses the sulphide of carbon, which is the heavier, and causes it to rise in the tube up to the level a'a', where it saturates a cotton wick, which is then lighted. The upper end of the tube is surmounted with a chimney, PQ. which quickens the draught.
The combustion may be retarded or quickened at will by causing the level bb of the water to rise or lower.
The burner is placed in the room to be disinfected, which, after the wick has been lighted, is closed hermetically. When all the sulphide is burned it is replaced by water, and the lamp goes out of itself.
The combustion proceeds with great regularity and without any danger. It takes about five and a half pounds for a room of 3,500 cubic feet capacity. The process is sure and quite economical, since sulphide of carbon is sold at about five cents per pound, which amounts to 25 cents for a room of 3,500 cubic feet capacity. The burner costs ten dollars, but may be used for an almost indefinite period.
The process of producing sulphurous acid by the combustion of sulphide of carbon is, as may be seen, very practical and advantageous. It does not affect metallic objects, and it furnishes a disinfecting gas continuously, slowly, and regularly.
Mr. Ckiandi's burner may also be applied in several industries. It is capable of rendering great services in the bleaching of silk and woolen goods, and it may also be used for bleaching sponges, straw hats, and a number of other objects. - La Nature.