164 INTERNATIONAL CONGRESS OF VITICULTURE 



Directly beneath the inlet from the retort to the chamber there is deposited 

 a considerable quantity of sulphur more or less run together in a compact 

 mass. This lump sulphur is sold as refined lump or "virgin rock." Around 

 the edges of this mass and out in all directions toward the finer grades there 

 is a deposit which is known as "honey-comb" sulphur. This may be thrown 

 back into the retort and resublimed or it may be ground and sold as refined 

 flour sulphur. It is thus seen that the sublimed sulphur which is deposited 

 in the chamber ranges all the way from the very finest particles in the most 

 remote parts of the chamber through the coarser and coarser grades to the 

 lump sulphur which is deposited directly beneath the inlet from the retort. 



All of the non-volatile impurities are left in the retort and any impure- 

 ties found in the sublimed sulphur must be of a volatile nature. Im- 

 pureties found in crude sulphurs which can not be removed by the sublima- 

 tion process are arsenic and asphaltum, both of which would be carried over 

 along with the vapor of sulphur. Some crude sulphurs contain an appreciable 

 amount of silicious material which will remain behind in the retort. 



Most of the sulphur which is refined in the United States is of a very 

 pure character, being 98 to 99.5 per cent pure and is very free from arsenic 

 and asphaltum so that the sublimation process is chiefly for the purpose of 

 obtaining a desirable physical condition. 



KINDS OF SULPHUR. 



Sublimed: This term may be properly applied to any sulphur which has 

 been purified by the process of sublimation. Sublimation may be described 

 as bringing a solid into a state of vapor by means of heat, which, on cooling, 

 returns to a solid state. This definition, therefore, includes the refined lump 

 (or "virgin rock") and "honey-comb" as well as the flowers of sulphur of all 

 degrees of fineness. 



Flowers. The word "flowers" shouM be used to designate the finest and 

 fluffiest grades of the sublimed sulphurs only. It would be a difficult matter, 

 however, to say just when a sulphur is entitled to the use of the word. Asa 

 consequence, the coarsest grades of sublimed sulphur have been sold as 

 flowers of sulphur. 



All grades of sublimed sulphur contain traces of sulphur dioxide which 

 in time may be oxidized into sulphuric acid. The amount is usually small, 

 but enough to give it a sour taste. It was noted by Blodgetti that a decidedly 

 acid taste was always noticed in sulphurs which gave trouble in the sulphur- 

 ing machines. Samples of troublesome sulphur were analyzed and in one 

 case nearly two per cent, of sulphuric acid was found. The lumping of the 

 sulphur was attributed to the presence of the sulphuric acid which attracted 

 moisture from the air and kept the su'phur in a damp condition so that it had 

 a tendency to pack when pressed together in the hands. No sulphurs of such 

 remarkably high sulphuric acid content have been seen by the speaker but 

 an occasional sample has been examined which stuck more or less to the 

 sides of glass containers and upon analysis showed an appreciable quantity 

 of sulphuric acid. Sulphur sacks occasionally rot and this is attributed to 

 the presence of sulphuric acid. It is quite fortunate that instances of this 

 kind are very rare in California. 



Blodgett, P. M., New York Agr. Exp. Sta., Bu 1 . 395, 1915. 



