460 Journal of Applied Microscopy. 



The mineral matters are sulphur, calcium, magnesium, iron, manganese, 

 silicates. 



The yolk, or natural suint — wool fat — contains, besides the fatty, saponified 

 matter, soda and potash, which the animal, during natural feeding, absorbs from 

 the plant. We have said that wool, like hair, horns, hoofs, and feathers, belongs 

 to the albuminoid family, and as in all living animals, the albumin, casein, and 

 fibrin matters constantly change among themselves, from one into another, 

 their specific analyses would differ but little. To illustrate our meaning more 

 fully, we give an analysis of mixed hair, wool, and feathers, and horny sub- 

 stances — second of pure wool : 



No. 1. No. 2. 



Mixed Hair, Wool, Feathers, Pure Wool. 



Horny Sabstance. 



Carbon, 50.45 50.20 



Nitrogen, 16.60 17.45 



Hydrogen, 6.24 6.60 



Oxygen, 23.21 21.85 



Sulphur, 3.50 3.90 



We notice but a slight difference, and not sufficient to distinguish between 

 the two. The ash of these samples represented 1.85 per cent, and 2.1 per cent., 

 respectively, and is here accounted for along with the carbon. Test No. 2 : 

 Before analysis the wool was washed in lukewarm, distilled water, and dried 

 at 110 degrees F. for three hours. Doctor Kleiner once recorded a sulphur 

 analysis of 9 per cent, in Saxon-Merino wools. We have never been able to find 

 more than from 2.50 per cent, to 4 per cent., whereas the yolk suint, and natural 

 wool fat varies with the district, the climate, and the breed ; it ranges between 12 

 per cent, and 65 per cent, of the weight of the wool ; the amount of potash 

 varies inversely according to the amount of fat or yolk, i. e., the higher the per- 

 centage of fat or yolk, the lower the percentage of potash. A low percentage of 

 grease invariably means a higher percentage of potash. Nature seems to have 

 provided these exudations as a protection from the weather. In the tropics the 

 sheep breeder pays great attention to artificially supplying the yolk, or grease to 

 the sheep in a preparation consisting of butter and oil, potash and tar, sapon- 

 ified into a kind of green soap, w^hich is put on the backs of the sheep. The 

 uses of the microscope in studies of this kind, however, are so many and various 

 that their further consideration may be continued profitably at another time. 



Ernest Fahrig, William P. Wilson, Sc. D., 



Chief of Laboratories. Director. 



To obtain expanded specimens of hydioids or other small forms, draw 

 nearly all the water from the watch-glass containing them, and when they have 

 expanded again, pour hot corrosive sublimate over them. If this is done quickly? 

 the organisms will be fixed before they have time to contract. From two to five 

 minutes is long enough to leave them in the sublimate, as the hot solution acts 

 rapidly. 



