1034 transa9ti0ns of the american institute. 



New Green Pigment. 



Among the substitutes proposed for the dangerous green containing 

 arsenic, is that produced bj M. Moulin, lie mixes 100 parts of a 

 hot sohition of zinc in hydrochloric acid, with from one to fifteen 

 parts of a hot solution of the oxyd of cobalt in hydrochloric acid, 

 the ])roportion being varied according to the shade of color required. 

 A solution of carbonate of soda is then added to the mixture, when 

 a precipitate of the mixed hjdrated carbonates of zinc and cobalt is 

 formed. The chlorine in the first mixture unites with sodium in the 

 carbonate solution, forming common salt, which is removed from the 

 precipitate by washing it with a large quantity of water. The pre- 

 cipitate is then dried on chalk or gypsmn plates, and subsequently 

 heated to at least 1,000 deg. C, when it assumes a yellow color, but 

 on cooling it becomes green. By using sulphate of alumina in place 

 of a portion of the zinc in the first mixture, a bluish tinge may be 

 given to the pigment. 



Cotton Waste as a Manure. 



A French cotton spinner has used his cotton waste, for the last ten 

 years, for seed beds and early crops. He mixes the waste with stable 

 manure, and thus claims to avoid the burning and chills which 

 manure alone often causes. The waste, applied to an asparagus bed 

 in a layer about eight inches thick, was found to protect it from snow, 

 and to so hasten the growth of the plant that tender and well flavored 

 aspai-agus had been gathered in the midst of winter. It was pretty 

 generally thought that cotton waste is too valuable to be used as 

 manure. 



Omnimeter. 



This name is given to a new and ingenious instrument designed 

 by M, Eckold, It is used in measuring distances, altitudes and 

 angles. It consists: 1, Of a graduated circle to read off each ten 

 seconds in the measurement of horizontal angles ; 2, Of a powerful 

 telescope, revolving in a plane perpendicular to the graduated circle ; 

 3. Of a microscope of high powers, connected with telescope, and 

 moving with it ; 4. Of a highly ssnsitive level lying upon a rule of 

 a fixed length, say twent}- centimeters ; 5. Of a scale fixed vertically 

 at the extremities of the rule, at a distance coincident with the opti- 

 cal axis of the microscope, which scale is divided into half millime- 

 tres, from one to 200 ; 6. Of a microscopical screw movement con- 



