CHEMISTRY. 295 



mined the ammonia existing in the air both in the interior and suburbs of 

 Paris. 



Mr. Lawes and Dr. Gilbert have published the results of an inquiry into the 

 quantity of ammonia and nitric acid in rain falling at Rothamstead, in Hert- 

 fordshire. The methods of determining small quantities of nitric acid are at 

 present so imperfect, that Messrs. Lawes and Gilbert have not thought it well 

 to publish then: results as to this substance, but they are led to believe that in 

 quantity it exceeds that of ammonia in rain. Besides the names we have 

 mentioned in connection with these researches, other continental and English 

 chemists might be referred to, if circumstances admitted of greater amplifica- 

 tion. It is, however, obvious, that in this hurried sketch we have omitted all 

 notice of many investigations on this and other subjects of agricultural che- 

 mistry which might weh 1 claim attention in a more extended review. 



Finally, we must not omit to mention, that the trade hi artificial manures, 

 which is rapidly rising into such national importance, especially in England, 

 is receiving the most important aid at the hands of chemical science. Not 

 only are the various waste substances of manufactures and of daily life 

 worked up into available form, but the manures produced by chemical means, 

 more especially the superphosphate of lime, are daily improving in character, 

 mainly through the suggestions of chemists who have specially devoted them- 

 selves to this branch of science. Fresh sources of guano have also been 

 discovered, and new supplies of substances useful to the farmer have in several 

 places been obtained. 



It is, therefore, not without reason that we congratulate ourselves on the 

 progress which has within the last five years been made by that department 

 of agriculture which is based upon chemical science. 



ON THE EMPLOYMENT OF HYPOSULPHATE OF SODA IN ANA- 

 LYTICAL CHEMISTRY. 



Dr. "W. Tofal recommends the more frequent emplojnnent of hyposulphate 

 of soda in chemical analysis, instead of sulphureted hydrogen. According 

 to him, it can be also used to evolve sulphureted hydrogen ; if a piece of 

 zinc is placed in dilute hydrochloric acid, and a few drops of a solution of 

 hyposulphate of soda added, sulphureted hydrogen is evolved. If now to 

 this mixture a solution of a salt of lead, bismuth, cadmium, &c., is added, the 

 sulphurets of the corresponding metals are precipitated. Ann. der Chem* 

 und Pharm. 



IMPROVEMENTS IN THE PRESERVATION OF ANIMAL SUBSTANCES. 



Jean "Wothly, of Zoffinger, Switzerland, has obtained a patent for the 

 following method of ' preserving meat: The meat is first cut into pieces of 

 about ten pounds hi weight, and separated from the bones. These are then 

 dusted over with sugar and salt, and allowed to stand about two days, and 

 are then subjected to pressure, in order that ah 1 the blood and serous matter 

 may be forced out ; or hi place of being pressed, they are moderately cooked 

 before packing. Tli^- are then placed in casks lined with melted fat. 



