ON ARTIFICIAL REFRIGERATION. 



Tahlc of crtjogcns and crijolnidrafes. (Guthrie.) 



915 



Name of salt. 



Sodium bromide 



Araraonitim iodide 



Sodium iodide 



IVitassiuiu iodide 



Sodium cbliuide 



Stroutium chloride 



Ammonium sulphate. . 

 Ammouium bromide . . 



Ammonium nitrate 



Sodium nitrate - , 



Ammouium chloride . . . 



Potassium bromide 



Potassium cliloride 



Potassium (dii-omato . . . 



Barium chloiide 



Slrontiuui nitrate 



]SIauucMium sulphate. . 



Zinc sidphate 



Potassium nitrate 



Sodium carbonate 



Copper sulphate 



Iron STd])l!ato 



Potassium sulphate. . . 

 Potassium Idchromate . 



Parium nitrate 



Sodium sulpliate , 



Potassium chlorate 



Ammonia alum 



Mercury perchloride. . : 



Formula. 



IN'a Br . 

 NUjI. 



Nal... 



KI 



NaCl 



Sr( Ij + CHjO 



Nn4S04 



NH4B„ 



XU4NO3 



XaNOs 



NHiCi 



KBr 



KCl 



KjCrOj 



BaCl2+2n.iO 



Sr^NOj 



MirSOj + THjO 



ZuS04+7n20 



KNO3 



Xa.COs 



CuSOj + SHjO 



PeSOi+THaO 



ICSOj 



KjCrsO, 



BaUNOa 



KajSOj + lOHjO 



KCIO3 



AI2N4H2SO4+I2H2O. 

 HgCl^ 



-18 



-17.5 



-17 



-17 



-10.5 



-10 



-13 



-10.5 



-10. 2 



- 7.2 



- G 



- 5.3 



- 5 



- 3 



- 2. 2 



- 2'" 



- 1.7 



- 1.5 



- 1 



- 0.9 



- 0.7 



- 0.7 



- 0.4 



- 0.2 



-17 



-17 



-17 



-17. 2 



-17.5 



-15 



-13 



-11.4 



-12 



- 8 



- 



- 5 



- 7 



- 2.G 



1.2 



1 



0.8 



0.7 



0.5 



0.2 



0.2 



o o 





8.1 



C.4 



5.8 



8.5 



10.5 



22. 9 



10.2 



11.1 



.5.72 



8.13 



12.4 



13.94 



16.01 



18.8 



37.8 



33.5 



23.8 



20.0 



44.0 



92. 75 



43.7 



41.41 



114. 2 



292. 



259.0 



105. G 



222. 



201.4 



450. 





41.33 

 55.49 

 59. 45 

 52.07 

 23. 00 

 27. .57 

 41.70 

 32.12 

 43.71 

 40.80 

 19.27 

 32. 15 



20. 03 

 36.27 

 23.2 

 25.99 



21. 86 

 30.84 

 11 20 



5.97 

 10. 89 

 10.92 

 7.i^9 

 5.30 

 5.30 

 4. 55 

 2.93 

 4.7 

 3.24 



41.61 

 57.6 

 59.39 

 51.72 



27.5 



42. 2 



32! 17 



43.26 



41.3 



19.27 



31.80 



20.07 



36.41 



24.0 



26.91 



17.35 

 7.5 



2.88 

 "42' 

 '3.' 29 



Professor Guthrie lias, from the evidence thus adduced, enunciated 

 the general law that if we define as similar salts either (1) those which 

 consist of the same acid united with bases belonging to the same chem- 

 ical group, or (2) those which consist of the same base united with acids 

 belonging to the same group, or those whose bases belong to the same 

 group, and whose acids belong to the same group — then, of similar 

 salts, tlie one u'lucli produces the greatest cold iclicn used in a freezing mix- 

 ture unites as a cryohtjdrate unth the fewest molecules of loater. And to 

 the following law there seems to be only one pronounced exception : The 

 temperature at ivhich the cryohydrate is formed is the same as the tempera- 

 ture of the corresponding freezing-mixture. This latter law, however, has 

 to be taken with reserve as far as those salts are concerned which, like 

 chloride of aluminium and cliloride of magnesium, decompose water, and 

 also m regard to those bodies which, like chloride of calcium, unite with 

 water under the liberation of much heat. 



L.— CHLOEIDE OF CALCIUM ICE-MACHINE. 



The first practical cry gen-machine was patented in 1855 by IMr. C. 

 W. Siemens under the title " Improvements in coohng and in freezing 

 water and other bodies." In the apparatus required for these pm-poses 



