CHEMISTRY. (CHEMICAL ANALYSIS.) 



155 



them were found to be thoroughly impregnated 

 with this granular copper powder, some of the 

 granules being so large as to take on the form 

 of flakes. The larger ones were partly rolled 

 up, so as to fit in the irregular pores of the wood. 

 An analysis of the powder showed that it con- 

 sisted of 95.01 per cent, of copper. Microscopic 

 examination showed that only the outer annual 

 rings contained an appreciable quantity of the 

 metal, while the earlier rings showed only a trace 

 under the microscope, and those nearest the heart 

 none on analysis. This distribution is unex- 

 plained. The origin of the copper is undeter- 

 mined, but native copper occurs in the soil; yet 

 if it was assimilated from the soil it should have 

 been found in all the rings, and not chiefly in 

 the outer ones. The fact that the copper was 

 found in the metallic state raises the question 

 of the form in which it is found in plants gen- 

 erally. 



A case of poisoning reported upon by L. Barthe 

 was said to be traced to an enameled saucepan 

 of the familiar kind white inside and deep blue 

 outside. While some French enamels have been 

 found to contain as much as 52.51 per cent, of 

 oxide of lead and 3.74 per cent, of arsenic acid, 

 the enameled utensil in question in this case did 

 not contain either of these substances, but did 

 contain large proportions of silica, tin, and alumi- 

 num, and small quantities of zinc, lime, and 

 potash, with traces of iron and cobalt. The au- 

 thor was therefore of the opinion in this case 

 that the enamel was not to blame. 



At the meeting of the British Association Prof. 

 Hanriot, president of the chemical section of the 

 French Association, communicated a short ac- 

 count of the excretory products of plants, in 

 which he discussed the mutations of nitrogen in 

 the vegetable kingdom, as illustrated by his own 

 observations of the occurrence of asparagine 

 among the secretions of plant roots. When passed 

 into the soil the product would in all probabil- 

 ity be oxidized to nitrates, and thus become di- 

 rectly available for plant life. 



The subject of the properties of soaps was 

 brought up at a meeting of the Nottingham, 

 England, section of the Society of Chemical In- 

 dustry in a paper, by F. J. R. Carulla, on The 

 Function of Boric Acid in Soap. The author 

 found that boric acid was of great value to de- 

 stroy alkalinity, but that it could not remain 

 in the free state in the wash water when the 

 soap is put to use. It can have no antiseptic 

 effect, but is invaluable for the introduction into 

 the soap of antiseptics that require freedom from 

 alkali. The chairman of the meeting, Mr. James 

 O'Sullivan, said that the matter was of some 

 importance, as boric acid in 2-per-cent. solution 

 was used for the eyes, and of course a boracic 

 soap would not have the effect of this solution. 

 Carbolic acid would similarly react in the soap, 

 and be rendered inert. Mr. S. J. Pentecost did 

 not find a moderate percentage of alkali carbon- 

 ated alkali, not caustic in a soap injurious to 

 the skin. In answer to questions, Mr. Carulla 

 said that an addition of so much as 5 per cent, 

 of boric acid would make the soap difficult to 

 lather. Idiosyncrasy entered into the question 

 of the use of soap as well as into other things. 

 Some people could use a soap that would be 

 very irritating to others. The object of using 

 an antiseptic soap was to get rid of disease germs 

 and prevent their transmission from one person 

 to another. With the increasing use of super- 

 fatted soaps for toilet purposes, and the fact 

 that disease germs can live and multiply in oils 

 and fats, it is quite likely that much disease is 



transmitted from one person to another by using 

 the same tablet of soap. This could not happen 

 with a genuine antiseptic soap. Then, again, 

 disease germs are washed off the skin and car- 

 ried into the water. They will remain there in 

 long contact with the soap solution, which, if 

 strong enough, will put an end to their future 

 power for harm. Mr. Kipping, F. R. S., said that 

 it was easy enough to render extensive surfaces 

 of the skin, such as the hands, antiseptic even 

 with plain water; but for such places as under 

 the finger nails, which could not be readily dried, 

 and might form nests for bacteria, the resulting 

 prolonged contact with the solution of an anti- 

 septic soap was obviously a great safeguard. 



The disinfecting power of common soap hav- 

 ing been demonstrated by the experiments of 

 Koch and others, the investigation has been con- 

 tinued by M. Serafini, of the University of 

 Padua, in experiments to determine the exact 

 condition in which the solution of soap is effect- 

 ively active. M. Serafini concludes that soap, 

 whether of soda or potash, has a well-marked 

 disinfecting power, which does not depend only 

 on the action of the alkaline base, whether com- 

 bined or not with fatty acids, but results from the 

 saline combination which takes place. The free 

 alkalinity of soaps is generally too weak to pro- 

 duce a disinfecting action. The activity resides 

 in that part of the soap which is soluble in cold 

 water. Substances that precipitate soap dimin- 

 ish proportionately the disinfecting power of the 

 solution, and this power is likewise diminished 

 when the solutions are in a medium rich in car- 

 bonic acid. Increase of temperature favors the 

 disinfecting power of soap solutions, both through 

 the direct effect of heat and by increasing the 

 proportion of the soap dissolved. The disinfect- 

 ing power of soap being related to its constitu- 

 tion as an alkaline salt of a fatty acid, that 

 power is diminished in commercial soaps by what- 

 ever diminishes the proportion of those salts in 

 them, as by the presence of water, and foreign 

 substances. This power is consequently reduced 

 in resinous soaps. In laundries the disinfecting 

 power of soap is neutralized to a considerable 

 extent by the presence of albuminoid matters in 

 the goods, which prevent its penetrating the 

 pores. Hence it is necessary to take account of 

 the solubility in soap of the soiling matters. 

 Soft soaps are weaker in operation by the facil- 

 ity with which they absorb water, and in colored 

 soaps the disinfecting power is weakened by the 

 presence of the coloring matter. The author did 

 not himself make any experiments with soaps 

 which had been charged with disinfectants, but 

 observers generally agree that the soaps called 

 disinfecting are not more efficacious than com- 

 mon soaps. The disinfecting substances some- 

 times contribute by their action on the soap to 

 decompose it and diminish its power. Above all 

 things, the soap ought to be pure and to contain 

 as little water as possible. 



An apparatus for the industrial production of 

 ozone has been devised by M. Otto, of Paris. 

 It is claimed to be practical, and to avoid the 

 difficulties heretofore encountered in preparing 

 this substance on a large scale. 



An inherent fault in all acetylene generators 

 is the after-formation of gas which takes place 

 when the direct contact between the carbide of 

 calcium and the water has ceased. This genera- 

 tion is due to the action of the residual water 

 contained in the pores of the carbide, to the con- 

 densation of water on the surface of this car- 

 bide, and to the absorption of aqueous vapor. 

 Measurements of the quantities of gas liberated 



