373 



potasli of tlio Northern States. This pearl pan or lalc^ is known in this country as 

 Allcali Lake. There appears to be an nndcrpjround deposit of alkali -which is constantly 

 rising to the surface in a kind of gas or vapor Avhich crystallizes on the surface of tlw 

 ground in one continuous and complete crnst over the whole pan, in a thickness ranging 

 from J to H inches. The Mexicans use it for the manufacture of l)ar-.soai), which is 

 far superior to any rosin or common bar-soap of the United States. When tliis crust is 

 t.aken off the ground another complete crust forms in a week ; and thus it appears that 

 fifCy-two ci'ops or gatherings may bo made during the year, and thousands of pounds 

 can bo obtained at one time. * * * a Mexican arrived in this city yesterday with 

 aloa.d of these pearls, containing 10 fauegas, (equal to 2} English bushels per fanoga,) 

 and soldtho same to Ernest Augustine, merchant, for the i^urpose of u)akiug soap, for 

 the sum of $1.25 per fanega ; and from which I gathered these specimens. If the De- 

 l)artment will have thcni analyzed, I shall be pleased to know the truo nature of 

 these pearls. 



The specimens were averaged and a sample submitted to analysis 

 with the following results : 



Moisture n.81G3 



Potassium sulphate .- 1. 3000 



Sodium sulphate ." 11.4948 



Sodium chloride .'). 09G7 



Sodium carbonate 7, 3915 



Sodium bicarbonate 70.9002 



100.000 



From the above it will be seen that this is substantially a group of 

 sodium salts, consisting chiefly of bicarbonate. The potassa, after sub- 

 tracting the sulphuric acid with which it is united, amounts to less than 

 1 per cent. 



]S"oTES FEOM FoEEiaN JOURNALS. — Soil temperature. — M. Becquerel, 

 in his experiments with the electric thermometer, has found that calca- 

 reous and siliceous soils absorb and retain more heat than argillaceous and 

 humid soils, and that the temperature of the air above the former, is 

 diminished while it is rising to its highest i)oint, but above the argil- 

 laceous soil it is increased. These conditions are reversed when the soils 

 are diminishing in temi^erature. 



The practical inference from this is that vegetables liable to be injured 

 by frost should be planted on calcareous or siliceous soils, for the danger 

 of frost-injury is during the hours when the soil is losing heat. If, how- 

 ever, it is desirable to raise such vegetables on moist clay soils, they 

 sliould be protected from the cooling action of the earth. 



Influence of vegetahle mold on soils. — M. Schloesing concludes, as the 

 result of his investigations, that vegetable mold acts favorably on all 

 qualities of soils. On loose sandy soils, vegetable mold has a tendency 

 to consolidate the particles and render the soil more compact and con- 

 sequently more retentive of moisture and tlie fertilizing gases. On the 

 other hand, stifi", compact soils are rendered friable and mellow by a 

 mixture with vegetal3le mold. The improvement in the mechanical 

 condition of the soil may be regarded as chief effect of vegetable mold. 



Utilization of sawdust. — M. Gustave Hueze says that, though sawdust 

 decomxDoses very slowly, yet it may be economically used as litter in 

 stables, and left for several months in contact with the solid and liquid 

 excrement of animals, which it readily absorbs. It may also be com- 

 posted with quick-lime and left in a heap for about a year. Additions 

 may be made to this heap from time to time, but, when such additions 

 are made, the whole heap should be well stirred. It will be improved 

 by being frequently saturated with urine or sewer-water. Sawdust thus 

 treated may be used on partially exhausted soils with great ad- 

 vantage. 



