88 THE CALIFORNIA 



obtain as much food from one acre as from two or three 

 acres of other soils ; in that mulberry soil, trees seven 

 years old measure from two to three feet in circumfer- 

 ence, and shoots one year old, from ten to twelve feet 

 long ; and we have any amount of such soil in all the 

 valleys of California. I have remarked a great quan- 

 tity of it in our beautiful and healthy valley of San 

 Jose, but have observed it more generally in the Sacra^ 

 mento valley. We can say that we have hundreds of 

 thousands of acres of such soil in California, and it is 

 incalculable the quantity of silk we can produce we 

 could supply the whole world with this article. But I 

 must return to the' main subject of this letter. 



SILK MANUFACTURE. 



The silk manufacture may be divided into two branch- 

 es : first, the production of the raw silk ; second, its 

 filature and preparation in the mill for the purposes of 

 the weaver and other textile artizans. The threads, as 

 spun by the silk worm and wound up in the cocoon, are 

 all twins, in consequence of the twin orifice of the nose 

 of the insect, through which they are projected ; these 

 two threads are laid parallel to each other, and are 

 glued more or less evenly together by a kind of glossy 

 ^varnish, which also envelops them, constituting nearly 

 twenty-five per cent, of their weight. Each ultimate 

 filament measures about one-twothousandth of an inch 

 in average, fine silk, and the pair measure fully one- 

 onethousandth of an inch in the raw silk, as imported 

 from Italy, France, China, etc. ; several of these twin 



