[ 329 ] 

 XXVIII. Intelligence and Miscellaneous Articles. 



ON THE HEAT PKODUCED BY MOISTENING PULVERIZED BODIES. 



NEW THERMOMETR1CAL AND CALORTMETRICAL RESEARCHES. 



BY TITO MARTINI *. 

 TN my second paper presented, last April, at the R. Istitufco 

 -*- Yeneto, I dealt with the calorific phenomena observed in 

 moistening pulverized bodies. The method of experiments has 

 already been described f ; that is to say, of an arrangement whereby 

 the liquid ascended to the powder, thoroughly dried, placed in a 

 glass tube separated from it by a piece of light linen cloth. In 

 this second series of experiments some modifications were intro- 

 duced in order to keep the powder as dry as possible till the be- 

 ginning of the experiment. The thermometer-bulb was placed in 

 contact with the upper stratum of powder, it having been noticed that 

 the increase of temperature was more marked from layer to layer. 



In the following tables are indicated some of the principal 

 results obtained with pure charcoal and pure silica (Si0 2 ). 



Pure Charcoal (gr. 25). 



Name of the Liquid. 



Te »p. 

 of the 

 Air. 



Temp, 

 of the 

 Liquid. 



Temp. 



of the 



Charcoal. 



Max. 

 Temp. 



Increase 



of 

 Temp. 



Liquid 

 absorbed 

 in cm. 3 



35 cm. 3 



30 



28 



32 



34 



29 



Distilled water 



Absolute alcohol 



Sulphuric ether 



o 



9 



19-16 

 1071 

 19 30 

 20-10 



710 



8-25 

 1910 

 11-10 

 19-42 

 2015 



6-12 



c 



9 20 

 19-29 

 10-89 

 19-60 

 20-30 



7-20 



34-30 

 4505 

 29-48 

 44-60 

 3360 

 28-90 



25-10 

 2576 

 1859 

 25-00 

 13-30 

 21-70 



Acetic ether 



Benzene 



Bisulphide of carbon. 



Name of the Liquid. 



Temp, 

 of the 

 Air. 



Temp, 

 of the 

 Liquid. 



Temp, 

 of the 

 Silica. 



Max. 

 Temp. 



Increase 

 of the 

 Temp. 



Liquid 

 absorbed . 



Distilled water .. 



Absolute alcohol 



Sulphuric ether 



19-00 

 19-27 

 1465 

 20-19 

 19-50 

 18-84 



18 96 

 18-87 

 14-60 

 2025 



19 49 

 18-95 



19-30 

 I960 

 14-69 

 20-70 

 19 60 

 19-32 



41-90 

 4575 

 4621 

 50-80 

 31-70 

 3105 



22-60 

 26-15 

 31-52 

 30-55 

 1210 

 11-73 



37 cm. 3 



36 



35 



7 



40 

 38 



Acetic ether 



Benzene 



Bisulphide of carbon. . . 



1 made also many experiments in order to determine the number 

 of calories produced by moistening powder. I adopted a special 



* " Intorno ad calore che si sviluppa nel bagnare le polveri. Nuove 

 ricerche termometriche e calorimetriche." Atti del H. Istituto Yeneto, 

 t. 9, serie vii. p. 927. 



t Atti del R. Istituto Veneto, t. 8, serie vii. p. 502; Phil. Mag. 

 vol. xliv., August 1897. 



