COMPOSITION OP LIME-SULPHUR ANIMAL DIPS. 7 



In these three equations v may be taken as practically a constant 

 quantity. Therefore eliminating v in equations 1 and 2 and solving 

 for W we have'W=17.1. In the same way from equations 1 and 3 

 we have W=16.9, and from equations 2 and 3, W=16.6. Accord- 

 ingly the utilization of the raw materials appears to become slightly 

 less complete with increasing concentration. 



OCCURRENCE AND RELATIONS OF CALCIUM SULPHITE. 



While Van Slyke and his coworkers undoubtedly established the 

 presence of calcium sulphite as a frequent ingredient in the sediment 

 from lime-sulphur solutions certain points seemed to call for addi- 

 tional investigation. Particularly was it desired to ascertain if les- 

 sened solubility of calcium thiosulphate in liquids heavily loaded 

 with other calcium salts might deserve consideration. 



EXPERIMENT 6. 



First, 50 c. c. of Preparation I was boiled for five minutes under gas and 

 reflux with 5 grams of calcium sulphite. After seA T eral days standing a 

 15-volume dilution gave a thiosulphate figure of 2.01 against a figure of 2.47 

 for a similar dilution of the original material. The other analytical figures 

 showed no change except very slight increases attributable to loss of water. 



Second, a portion of Preparation H was treated in the same way. A 5-volume 

 dilution prepared the following day gave a thiosulphate figure of 6.98 against 

 a figure of 5.53 for a similar dilution of the original material.. Boiling in the 

 same way for 15 minutes longer raised the figure to 8.54. 



Third, about 100 c. c. of Preparation I with 10 grams calcium thiosulphate 

 in a filled and sealed bottle was mechanically shaken several hours at room 

 temperature. A 15-volume dilution of the supernatant liquid had a thiosulphate 

 figure of 5.42 against the figure of 2.47 for a similar dilution of the original 

 material. A clear decanted portion of the concentrate thus treated was then 

 heated in a flask provided with a vertical air condenser for one hour in a 

 boiling-water bath. Much sediment appeared. After settling for several days 

 a 15-volume dilution had a thiosulphate figure of 2.91. The other analytical 

 figures showed no significant differences from the corresponding figures of 

 the original untreated Preparation I. The insoluble residue produced was 

 washed with cold distilled water until free from the yellow color of poly- 

 sulphids. A portion suspended in water showed a slightly alkaline reaction 

 with phenolphthalein, and absorbed a large quantity of strong iodin solution. 

 During addition of iodin solution the odor of sulphur dioxid became at one stage 

 very distinct. After excess of iodin had been added and then removed by 

 sodium thiosulphate the resulting liquid was strongly acid to methyl orange, 

 all of which reactions combined constitute conclusive proof of the presence 

 of sulphites. 7 



By Experiment 6 the equilibrium of the reaction CaSoOg^CaSC^ + S 

 is controlled by both temperature and concentration of the solution. 

 Highly concentrated solutions can dissolve in the cold much more 

 calcium thiosulphate than naturally occurs in them, but on heating 

 the above reaction progresses from left to right. On the other hand, 



