June, 1953] B. M. PATEL, G. K. WAGLE, M. R. PADHYE AND B. K. VAIDYA 91
content of wool which would necessarily vary with genetical and environmental
factors connected with the individual cases. Estimation carried out on various
types of samples, where such factors were known to a certain extent, emphasize
the caution which is necessary in attempting any correlation or wool quality with its
sulphur content.
Physico-chemical methods for the estimation of medullation were however
considered best for testing bulk medullation of a sample ; for here it was possible
that due to the larger differences in the surface area of fine, coarse and medullated
fibres, the rate of absorption should accordingly show variations. If this rate was
then measured under specified conditions, by an application of the laws of absorption
a relation may be obtained between the amount of the substance absorbed from the
solution and the surface area presented by the fibres in the sample. Calculations
of surface area in medullated fibres present some difficulty, due to the partially
hollow nature of the medulla, but these could be done by making one or two minor
assumptions. There is evidence to show that the behaviour of certain chemicals
(acids, alkalies, bromine and permanganate) absorbed by the two types of fibres
namely, the fine transparent solid wool and the coarse opaque and hollow hair fibres,
from equeous solution, is different. Adsorption experiments carried out with wool
samples varying in quality show that from the knowledge of an average fineness
of a sample and its corresponding absorption value (which "follows Fick's Law of
•diffusion) under specified conditions, the amount of medullation may be worked
out by correlating it with the total surface area, presented by the sample for absorp-
tion. Results obtained during the course of this work justify the hope that a study
of adsorption process in the two cases would ultimately give a method which could
lead to a quick determination of the amount of coarseness and hairy portion in a
specimen of wool.
Further work done along these lines particularly with dyes such as Kiton Red G
and Saffranine show preferential adsorption either in the cortex or medulla of the
wool fibres. Adsorption experiments with the dyes Saffranine and Kiton Red G
under standard conditions on non-medullated and medullated wools show that there
is a relation between medullation and the adsorption qualities of fibres.
The studies of moisture regain of the medullated and unmedullated fibre
show a variation of regain with medullation and also the conditions of humidity
and temperature. This characteristic, however, cannot be used for quantitative
estimation of percentage medullation because of complication of medullary cell.
The chromatographic studies of the medullated fibres, composition for amino-
acid has shown that the cystine content of the medullated fibre is less than that of
the wool.
These considerations hence show that the method adopted for estimation of
medullation during the course of present investigation from microprojection is
best suited for the regular analysis of the wool samples.
In the following papers of the series and extended statistical survey of the
quality of wool produced by different Indian breeds of sheep is proposed to be given
from the data collected in this laboratory as a result of enormous work on wool
analysis done in last ten years.