912 EEPORT OF COMMISSIONER OF FISH AND FISHERIES. 



I.— TABLE OF FEEEZING-MIXTUEES (GUTHEIE). 



The temperatures obtained on mixing the salt with three to six times 

 its weight of ice in lumps of the size of a i^ea downwards. 



Name. 



Sodium ■bromide 



Ammonium iodide 



Sodium iodide 



Copper chloride 



Potassium iodide 



Sodium chloride 



Magnesium chloride . . 



Strontium chhiiido 



Ammonium sulphate. . 

 Ammonium bromide.. 

 Ammonium nitrate ... 



Sodium uitrate 



Ammonium chloride .. 



Iron chloride 



Calcium nitrate 



Potassium bromide . . . 

 Aluminium chloride. . . 

 Potassium chloride ... 

 Potassium chmmate .. 



Barium (■lil(iri(l(^ 



Stronliniu nitrate 



Magnesium sulphate.. 



Zinc sulphate 



Potassium nitrate 



Sodium carbonate 



Copper sulphate 



Iron sulphate 



Potassium sulphate... 

 Potassium bichromate 



Barium nitrate 



Sodium suljiliate 



Potassium chlorate 



Ammonia alum 



Mercury perchlorido.. 

 Ammonium oxalate . . . 



Temperature. 



Formula of salt. 



NaBr 



NH,! i 



Nal 



Cu CI2 



KI 



NaCl 



MgClj + CHjO 



SrClj + CHaO 



2XlIi,S04 



Nn4Br 



NHjNOs 



NaNO, 



NH4CI 



PeClj (commercial) 



Ca2X03 + 4H20 



K Br * 



Al CI3 (in strong solution) 



KCl 



K2Cr04 



BaCl^ + 2n2 



Sr2N03 



MgS04 + 7n20 



ZuSOj + THjO 



KNUj 



NajCbj 



CUSO4+ SHjO 



PcSOj + THjO 



K2SO4 



Kj Cr, O7 



Ba2N03 



Na,SO4 + 10H2O 



KCIO, 



AI2NH42SO4+I2H2O 



IlgClj 



NH4CO2 



Cent. 



28.0 

 27.0 

 28.0 

 2(1.5 

 24.5 

 22.0 

 22.0 

 20.5 

 18.0 

 17.5 

 17.0 

 17.0 

 10.0 

 16.0 

 16.0 

 U.O 

 13.0 

 13.0 

 10.5 

 10.2 

 7.2 

 CO 

 5.3 

 5.0 

 3.0 



1.7 

 1.5 

 1.0 

 0.9 

 0.7 

 0.7 

 0.4 

 0.2 

 0.2 



Fahr. 



— 18.4 



— 16.6 



— 18.4 



— 15.7 



— 12. 5 



— 7.6 



— 7.6 



— 4.9 



— 0.4 

 + 1.0 



1.4 



1.4 



3.2 



3.2 



3.2 



. 6.8 



8.6 



8.6 



13.1 



13.7 



20.3 



21.2 



23.5 



23.0 



26.6 



28.3 



28.4 



30. 



30.2 



The temperatures here recorded are the lowest attainable for each 

 salt independently of the temperature of the salt and its degree of crys- 

 talhydration. 



Professor Guthrie has determined that a cryoliydrate undergoing solid- 

 ification may he considered physically as- the Jiomologue of a saturated salt- 

 solution in the act of hoiling. Comparing the decomposition of a salt- 

 solution by the loss of heat with the decomposition by gain of heat 

 when such a solution boils, the following ^joints may be noted : 



(1.) A solution poorer tliaii that satu- 

 rated at a given temiierature receives heat ; 

 vapor is formed. 



(2.) This goes on until saturation is 

 reached, the temperature rising. 



(3. ) Saturation may be reached by evap- 

 oration, boiling, or any other withdrawal 

 of water. 



(4.) Vapor separated from a liquid is re- 

 moved from the field of contention, unless 

 I the liquid be enclosed with the vapor. 



(1.) A solution poorer than the cryohy- 

 drate loses heat ; ice is formed. 



(2.) This goes on until the proportion of 

 the cryohydrate is reached, the tempera- 

 ture falling, 



(3. ) The cryohydrate may be reached by 

 freezing out ice from a weaker solution, or 

 by any other Avithdrawal of water. 



(4.) When ice separates from a liquid, 

 it remains in contact with the liquid, and 

 endeavors to redissolve therein. 



