366 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



sential to the reception and dilution of the acid employed in 

 superphosphate manufacture. 2. The phosphates are increased 

 one fourth in quantity from the alkaline phosphates and phos- 

 phoric acid of the soil; thus, if seventy-five units of phosphate 

 of lime are introduced, one hundred are withdrawn. 3. The 

 phosphates receive a new supply of nitrogen equal to from 

 two to four per cent, of ammonia from the soil. 4. The phos- 

 phates obtain five to eight per cent, of alkaline salts, contain- 

 ing one per cent, each of magnesia and potash, from the soil. 

 5. The phosphates receive, in addition, sixteen per cent, of 

 organic matter intermixed with the urea and uric acid, pos- 

 sessing the latent quality of evolving ammonia to the last 

 atom, and inducing nitrification, as well as the ammonia and 

 nitrates as returned in the analyses. On the other hand, 

 night-soil receives from phosphates the following advantages: 

 (a) Cementation; (b) solidification ; (c) deodorization ; (d) 

 portability by rail or sea in the service of agriculture ; (e) 

 the bringing within the pale of sanitary laws, contributing 

 - to health and to municipal revenues. It is even suggested 

 that the present superphosphate manufacture must ultimate- 

 ly pass over into night-soil utilization, either voluntarily or 

 by legislative enactment. 17 A, December 1,1871,214. 



PREVENTING HEATING IN GRAIN-STACKS. 



A simple instrument has lately been devised, under the 

 name of the hay-stack ventilator, for the purpose of ascertain- 

 ing and counteracting the heating in the interior of stacks 

 of hay or grain. This consists of a wrought-iron tube, about 

 three inches in diameter, which is long enough to reach into 

 the middle of the stack, and, like the Norton well-tube, is pro- 

 vided with a conical point at the tip, and pierced for about 

 two thirds its length with numerous holes. A screw ar- 

 rangement is affixed to the posterior extremity by which it 

 can be connected with an accompanying discharge-pipe. 



For use, this apparatus is to be driven horizontally into the 

 stack to be investigated, either by means of a mallet or by a 

 screw arrangement, and the temperature ascertained, after a 

 short interval, by introducing a self-registering thermometer. 

 Should the temperature be too high at any point in the stack, 

 a tin tube is to be affixed vertically to the outer end of the 

 iron tube, and an outward current of air from the interior of 



