December 25, 1885. J 



SCIENCE. 



567 



acid preparations round, smells a strong smell, and 

 feels safe. 



This notion probably arose from the fact that 

 carbolic acid is a very good deodorizer and a very 

 good antiseptic, and that the popular mind has 

 failed to distinguish between these properties and 

 those of a disinfectant. Indeed, it may be said 

 that the scientific mind made the same mistake 

 until the ubiquitous germ theory made its appear- 

 ance to explain, among other things, just what a 

 disinfectant was. A disinfectant must, according 

 to tliis theory, be a germicide ; and, if it is to be 

 of any use, it must kill the germs quickly, and 

 when used iu comparatively small quantities. 

 The question before us is to decide how far car- 

 boUc acid fulfils this indication. The first ex- 

 periments^ made with a view to answering this 

 question were those of Eosenbach,- who, in 1873, 

 showed by experiments on unhealthy pus that a 

 0.5-per-cent solution of carbolic acid did not' act 

 on this substance as a disinfectant, but that a 

 5-per-cent solution did. About the same time 

 Devalue^ proved that a 0.5-per-cent solution had 

 no effect on the anthrax bacillus. Similar experi- 

 mients by Braidwood and Vacher,"* and Dougall,^ 

 seem to show conclusively that vaccine virus is 

 not changed when subjected to the prolonged 

 action of a 1-per-cent solution of carbolic acid, 

 and that ia some cases it was not affected by a 

 2-per-cent solution. Sternberg ^ has also shown 

 that nothing less than an 0.8-per-cent could be 

 relied on to destroy the micrococci of pus and 

 septicaemia. 



The latest researches on this subject are those 

 of Gartner and Plagge.' These gentlemen, under 

 the supervision of Koch, carried on a careful and 

 elaborate series of experiments on thirteen differ- 

 ent species of micrococci, using solutions of 1 

 per cent, 2 per cent, and 3 per cent. One part of 

 pure culture was shaken up with forty-nine parts 

 of the carbolic-acid solution, and allowed to stand 

 for a longer or shorter time.® Then a small por- 

 tion of the mixture was placed in conditions favor- 

 able to growth. It was found that under these 

 circumstances the 1-per-cent solution did not act 

 at all as a germicide, that the 2-per-cent solution 

 failed to kill the germs in two out of the thirteen 



' An exhaustive resume of the literature on this subject 

 is to be found in the Medical news, xlvi. 317-320. 



2 Med. record, viii. 427. 



3 Comptes rendus, Ixxvii. 821-825. 



■* Brit. med. assoc, Scientific reports, London, 1876. 



■' Brit. med. journ., 1879, ii. 726-728. 



''• Amer. journ. med. sc, Ixxxv. 321-344. 



'' Archiv. klin. chir., Berlin, xxxii. 403-413. 



* In the different series of experiments the times were 8, 

 15, 30, 45 seconds, and 1, 3, and 5 minutes. 



cases, and that the 3-per-cent solution acted in all 

 cases as a disinfectant. A further series of ex- 

 periments showed that a 3-per-cent solution of 

 carbolic acid would probably act as an efficient 

 disinfectant when applied to the hands, to surgical 

 instruments, to dressings, etc. 



Earlier experiments ^ by the same authors, as 

 well as some of Braidwood and Vacher's experi- 

 ments, showed that in a gaseous state about 12.5 

 grams per cubic metre would be needed to disinfect 

 damp clothing, and 15 grams per cubic metre to 

 disinfect dry clothing. 



In view of these experiments, it seems very clear 

 that carbolic acid is of no value whatever when 

 used in any ordinary quantities to disinfect sick- 

 rooms, water-closets, clothing, etc., and is of 

 doubtful utility in any case unless the object to 

 be disinfected can be thoroughly soaked in a 

 solution at least as strong as 3 per cent. 



F. S. Bunker. 



MALTHUS AND HIS WORK. 



Two recent productions have come to our 

 notice, having for their chief subject the Malthu- 

 sian theory of population. Mr. Bonar's book - 

 contains a painstaking and intelligent accoimt of 

 Malthus' ' Essay on the principle of population,' 

 and the discussions which preceded and followed 

 it ; an impartial review of his other writings and 

 controversies ; and a brief narrative of his personal 

 life. Mr. Nossig's series of papers^ presents a 

 pretentious medley of learning unaccompanied by 

 insight, of that arrogance towards old wisdom 

 which a superficial acquaintance with modern 

 knowledge often induces in a shallow mind, and 

 of that amusing species of childishness which 

 manifests itself in writing down formulas having 

 a profoundly mathematical appearance to express 

 obvious truisms or crude scientific fancies. 



One cannot help feeling, on reading an article 

 like Nossig's, — written by an educated man, and 

 published in a scientific journal of high standing, — 

 that the way in which the doctrine of Malthus has 

 fared w4th a considerable part of the reading and 

 writing world is most discreditable to the average 

 human mind. That a doctrine pregnant with the 

 weightiest practical consequences in himian affau*s 

 should for a century be disputed m every way, — 

 with wisdom and with folly, with logic and with 

 sophistry, by fair means and foul, — is not surpris- 

 ing ; but that its opponents should still so often 

 fail to grasp the meaning of the doctrme itself is 



1 Deutsch. verein fiir oeflentliehe gesucdh. pflege. 



2 Malthus and his loork. By James Bonar, London, 

 Macmillan, 1885. 8°. (New Yoric, Harper.) 



3 Ueber die bevolkerung. By Alfred Nossiq. Kosmos. 



1885. 



