485 



Preparation op butter. — It is quite a coramon belief that batter 

 can only be made from sour miik, and chemists explain this on the 

 ground that acidity is necessary to destroy the membrane which envel- 

 opes the butter molecules, so that they are set free to combine with each 

 other after shaking'. Mr. E. H. Bauinhauer thinks he has disproved 

 this theory by the follovving- experiment : He first carried fresh milk to 

 his laboratory without shaking- or exposing it; this he divided in four 

 portions of half a gallon each, placing them in bottles of one gallon 

 capacity. One he left neutral, viz, as it came from the cow ; one was 

 acidulated with lactic acid ; one made slightly alkaline with carbonate of 

 liotash, (tliis became acid during the manipulation ;) and the fourth re- 

 ceived a greater quantity of carbonate of potash, and remained alkaline 

 throughout. The temperature was about 70° Fahrenheit. These bot- 

 tles were shaken violently for one minute by four men. When at rest 

 wart-like grains adhered to the glass, which, under the microscope, 

 looked like drops of fat of oval, but irregular shape, somewhat like mul- 

 berries. From minute to minute the shaking- was interrupted ; the 

 globules uniformly increased, and after eighteen minutes yellow butter 

 was obtained in all the bottles, in little masses like peas. According to 

 our author, the lactic acid could have had no influence in dissolving the 

 membranes of the globules, and, in fact, he doubts the existence of such 

 membranes. He thinks that shaking- at the proper temperature com- 

 bines the floating particles of butter; when the milk is too cold no but- 

 ter forms ; when too warm, a kind of emulsion is obtained, which, at a 

 low temperature, hardens, but is white and lesis translucent than good 

 yellow butter. Mr. Baumhauer promises the best success in butter- 

 making whenever proper attention is given to the temperature of the 

 milk, which ought to be between the narrow limits of 65'^ to 70° Fahren- 

 heit. 



Proper kind of water for washing wool. — Professor Trom- 

 nier, of the Agricultural Academy in Eldena, in reference to the impor- 

 tance of the quality and chemical composition of the water used for 

 washing the wool of sheep, whether before or after shearing, calls atten- 

 tion to the fiict that the matter to be removed by washing is quite com- 

 plex, and consists, in the main, of the non- volatile portion of the sweat, 

 the grease of the wool, abrasions of the epidermis, the dust from the 

 surroundings, and the dirt from the excretions of the animal. It has 

 an alkaline reaction from the prevalence of potassium, either in the form 

 of carbonate, or in its combination with grease as a kind of soap. Pure 

 water readily dissolves these potash CQmpounds, and the resulting solu- 

 tion is in itself a very good wash ; but when the water contains lime, 

 a decomposition takes place, and insoluble compounds of lime (either 

 carbonate or soap of lime) precipitate upon the wool and are removed 

 with the greatest difficulty Hence the necessity of avoiding calca- 

 reous water. Professor Trommer mentions an easy way to detect the 

 presence of lime, viz : a solution of soap in alcohol, when poured into a 

 tumbler of water, will make it rapidly turbid whenever it contains salts 

 of lime, while pure water remains clear for some time. When, however, 

 necessity compels us to the use of hard water, the addition of some 

 alkali is recommended, which sha,ll precipitate the lime in solution as 

 an insoluble carbonate. Caustic soda is the cheapest for that purpose. 

 The author enumerates some of the advantages arising from the wash- 

 ing of the wool after being shorn, remarking that the quantity of water 

 necessary for the operation being so much less, its qualities can be cor- 

 rected much more easily and with less expense, and its temperature 



