CHEMICAL SCIENCE. 233 



experiment upon the application of this mixture in disinfecting filth upon 

 the great scale, they have, nevertheless, proved that it can be advantageously 

 used in hospitals for deodorizing urine or fecal matters. 



The following inconveniences to which the use of the mixture in surgery 

 would give rise, are enumerated : 



It not only soils the clothes of the patient, but hardens them, and causes 

 them to weigh more heavily upon or about the wound; it imparts to the 

 bandages Avith which the poultices are covered a very tenacious rusty or 

 yellow color; it must be frequently renewed; and although it destroys putrid 

 smells, it retains a bituminous odor by no means agreeable to many persons. 



These inconveniences are of comparatively slight importance, it is true, 

 and may possibly admit of being remedied. 



Of the other disinfectants submitted to the committee, several were only 

 modifications of that of Corue and Demeaux. Vegetable tar, as shown by 

 Renault, may be substituted for coal-tar. With regard to the assertions of 

 some practitioners, that common earth, talc, flour, or other vegetable and 

 mineral powders, even poudrette, when mixed with coal-tar furnish a 

 more convenient and less costly disinfectant than that prepared with plaster, 

 the experiments of the committee have proved, that while coal-tar, mixed 

 with common earth, well dried, or with sand, is equally, or perhaps much 

 more, efficacious for disinfecting fecal matter as when mixed with plaster; 

 that while comparative experiments made from this point of view upon sul- 

 phate of lime, clay, charcoal, linseed-meal, and earth have resulted in favor 

 of the latter, the same is by no means true in surgery. When applied to 

 wounds or infectious suppurations these different mixtures were only par- 

 tially successful, having proved to be less efficacious than the mixed plaster 

 and coal-tar. 



Although the modifications of Corne and Demeaux's process have not 

 been particularly felicitous thus far, they have nevertheless served to confirm 

 the fact that in reality it is the coal-tar which acts the principal part as disin- 

 fectant in these various mixtures. 1 



1 The inefficiency of sulphate of lime as a general disinfecting agent, when used 

 by itself, may be readily demonstrated by the following experiment, which is of 

 interest in view of the fact that a belief in the utility of gypsum as a deodorizer 

 appears to be widely spread among recent writers. For that matter, we are told 

 by Paulet (Comptes Rendus, xlix., 199) that during the last twenty-five years more 

 than fifty authors of processes of disinfection have announced, each as he believed 

 for the first time, the use of plaster as a means of disinfection. 



If a mixture of about equal volumes of powdered gypsum and fresh urine be 

 introduced into a small phial, the mixture placed in a warm room and thoroughly 

 shaken several times a day until the urine has become putrid, it will be observed 

 that an exceedingly disagreeable odor will be developed, differing from ordinary 

 stale urine, inasmuch as it is unalloyed with the odor of ammonia. For the com- 

 plete success of this experiment, it is important that a large excess of sulphate of 

 lime should be present, and that the mixture should be frequently agitated, else 

 the whole of the carbonate of ammonia will not be decomposed, and will tend to 

 mitigate the fetor of the special odor of the putrid urine. So far from disinfecting, 

 in this case the sulphate of lime really destroys a deodorizing, or at least a masking 

 agent, ammonia; leaving free purified as it were, and unadulterated an odor, 

 the peculiar offensiveness of which is remarkable. Sulphate of iron being substi- 

 tuted for gypsum in this experiment, afforded a somewhat similar result, although 

 the odor obtained was a trifle less insufferable than that of the experiments with 

 sulphate of lime. It should be here mentioned that the odors in question were in 



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