In this investigation, analyses were made of the contents of hemicellulose, cellulose, crude lignin, crude protein and ash in 43 different plant materials. In addition, the proportions of various sugar anhydrides in the hemicellulose fraction were determined. The carbohydrate analyses were made by hydrolysing to monosaccharides, except for the uronic anhydrides, which were determined by the decarboxylation method. The sum of the cell-wall constituents thus determined was subsequently compared with Paloheimo’s membrane substances and crude fibre. Large variations in the cell-wall composition were found between different plant materials. Furthermore, there were large differences in the solubility of the cell-wall substances of different plant materials in the hydrolysing procedures used in determinations of membrane substances and crude fibre. The hemicellulose composition of different species in the same genus and even in the same family was found to be similar in definite plant parts and at definite growth stages. This appears to be a generic characteristic in the chemical taxonomy of plants.

A chemical method based on potassium fixation was developed for quantitative determination of vermiculite in soils. The cation-exchange capacity (CEC) of a sample is determined by washing with CaCl₂ and replacement of Ca with MgCl₂. The sample is then washed with KCl, heated to 110C overnight to dehydrate and collapse the layers of vermiculite and to fix K. The K remaining exchangeable is determined by NH₄Cl washings. The difference between these two CEC values gives the interlayer charge of vermiculite. A number of vermiculite standards and soil samples of widely different clay mineral compositions give remarkably near 100% totals when the vermiculite content is based on the average value of interlayer charge of 154 meq/100 g of vermiculite and when the other minerals present are appropriately determined (mica by K₂O, chlorite by ignition loss, montmorillonite by CEC measured by non-fixed K, quartz and feldspar by Na₂S₂O₇ fusion, allophane, kaolinite, and halloysite by selective dissolution in NaOH). The total CEC of vermiculite is 159 meq/100 g when the allocated external surface charge of 5 meq is included.

SynopsisPlant growth and the absorption of P by Italian ryegrass from nutrient solution was affected by P supply, whereas the distribution and accumulation of P within the ryegrass was largely determined by the kind of, and age of, tissue sampled. Blade 1, the youngest blade that was fully open and had a ligule, and H₂PO₄-P were selected, from 6 plant parts sampled and 2 forms of P determined, as the best combination to diagnose the P status of Italian ryegrass. About 750 ppm of H₂PO₄-P in blade 1 tissue was tentatively set as the critical concentration for growth of the ryegrass.

Two methods of determination of the volumes of felted wool balls with considerable accuracy are described. The first is an indirect method by computation from the directly determined average diameter of a ball, and a measuring procedure is given whereby this average diameter can be obtained accurately even when the shape of the ball is not per fectly spherical. However, the method involves subjective personal judgment and hence suffers from some lack of precision due to operator errors which may be introduced. In the second method, the volume is determined directly by saturating the ball with water and weighing it in this condition; theory and practice are fully described. The method is simple, very accurate (± 0.01 cm³), free from operator bias, and requires only normal laboratory equipment.

The amounts of K extracted from several soils of different K supplying power with solutions containing NaTPB were compared with the amounts taken up by intensive greenhouse cropping and with the amounts extracted with 1N NH₄OAc (exchangeable K). The best estimate of plant available K was the amount of K extracted from 2-g samples of nondried soil with 10 ml of 0.3N NaTPB in 15 min (r = 0.991). The decrease in the amount of K extracted by the same reagent in 16 hours, as a result of cropping, likewise was closely correlated with available K (r = 0.984). Exchangeable K determined in nondried soil samples was more closely correlated with available K (r = 0.971) than was exchangeable K determined in dried soil samples (r = 0.788).

Interaction between anions and soil colloids was governed by 2 antagonistic processes, anion exclusion and positive anion adsorption. The predominantly negative charge on the colloids caused anion repulsion; positively charged sites and chemisorption resulted in positive adsorption.Experimentally determined adsorption was the resultant of the 2 processes and yielded true net adsorption by correction for continuous anion exclusion.Assuming the Gouy Chapman theory of the electric double layer, de Haan calculated exclusion as the apparent distance from the colloid surface free from anions of different valency. The method was valid for systems containing monovalent and divalent cations and anions with an approximation for trivalent anions, and was extended to interacting double layers.The product of apparent distance of exclusion and of the colloid's specific surface was the volume of exclusion (V ex ), the same as the experimental adsorption value. Thus anion exclusion measurements yielded values for the colloid's specific surface. V ex was determined by a tracer method for Cl -, S0 42-, and P0 43-, and by potentiometric titration for Cl -. Adsorption of different anions could be determined simultaneously.Theoretical derivations were confirmed in experiments with fairly pure clays and in 12 Dutch soils, with special attention to phosphate adsorption. The correction for anion exclusion allowed refined measurements of anion adsorption and explained the bonding mechanisms between anions and soil colloids.

Interaction between anions and soil colloids was governed by 2 antagonistic processes, anion exclusion and positive anion adsorption. The predominantly negative charge on the colloids caused anion repulsion; positively charged sites and chemisorption resulted in positive adsorption.Experimentally determined adsorption was the resultant of the 2 processes and yielded true net adsorption by correction for continuous anion exclusion.Assuming the Gouy Chapman theory of the electric double layer, de Haan calculated exclusion as the apparent distance from the colloid surface free from anions of different valency. The method was valid for systems containing monovalent and divalent cations and anions with an approximation for trivalent anions, and was extended to interacting double layers.The product of apparent distance of exclusion and of the colloid's specific surface was the volume of exclusion (V ex ), the same as the experimental adsorption value. Thus anion exclusion measurements yielded values for the colloid's specific surface. V ex was determined by a tracer method for Cl -, S0 42-, and P0 43-, and by potentiometric titration for Cl -. Adsorption of different anions could be determined simultaneously.Theoretical derivations were confirmed in experiments with fairly pure clays and in 12 Dutch soils, with special attention to phosphate adsorption. The correction for anion exclusion allowed refined measurements of anion adsorption and explained the bonding mechanisms between anions and soil colloids.

The species cod (Gadus morrhua), coalfish (Gadus virens), ling (Molva molva) and torsk (Brosmus brosme) have been investigated. The samples were collected from newly caught fish and analysed fresh or after storage at below - 15°C. Vitamin B6 was determined microbiologically using Saccharomyces carlsbergensis as testorganism. Biotin was determined microbiologically with Lactobacillus plantarum. The results are summarized in Table 1-5, which have English subtitles. In general the filets were good sources for vitamin B6 and biotin. The white and red muscle contained about equal concentrations of vitamin B6, wheras the red muscle contained 6 to 22 times as much biotin as the white muscle. The liver is a fair source for vitamin B6 but a very rich source for biotin. The kidneys showed a difference between the front parts and the back parts, with about four times higher concentrations of both vitamin B6 and biotin in the latter. The results are briefly discussed.

In this investigation, analyses were made of the contents of hemicellulose, cellulose, crude lignin, crude protein and ash in 43 different plant materials. In addition, the proportions of various sugar anhydrides in the hemicellulose fraction were determined. The carbohydrate analyses were made by hydrolysing to monosaccharides, except for the uronic anhydrides, which were determined by the decarboxylation method. The sum of the cell-wall constituents thus determined was subsequently compared with Paloheimo’s membrane substances and crude fibre. Large variations in the cell-wall composition were found between different plant materials. Furthermore, there were large differences in the solubility of the cell-wall substances of different plant materials in the hydrolysing procedures used in determinations of membrane substances and crude fibre. The hemicellulose composition of different species in the same genus and even in the same family was found to be similar in definite plant parts and at definite growth stages. This appears to be a generic characteristic in the chemical taxonomy of plants. | Kasvien soluseinämät ovat koostuneet pääasiassa hiilihydraateista ja ligniinistä. Soluseinämähiilihydraatit ovat neutraaleista ja happamista sokeriyksiköistä rakentuneita polysakkarideja. Näistä on selluloosa yleisin. Muista käytetään tavallisesti yhteisnimitystä hemiselluloosa. Tutkimuksessa esitetään 43 eri kasvimateriaalin hemiselluloosa-, selluloosa-, raakaligniini-, raakaproteiini- ja tuhkapitoisuus sekä hemiselluloosafraktiosta lisäksi eri sokerianhydridien osuudet. Edelleen siinä verrataan soluseinämäaineiden summaa Paloheimon menetelmällä määritettyyn kettoaineeseen sekä raakakuituun. Tutkimuksessa todettiin suuria eroja eri kasviaineiden soluseinämäainekoostumuksessa ja samoin soluseinämäaineiden liukoisuudessa kettoaine- ja raakakuitukeitoissa. Saman kasvisuvun ja kasviheimonkin eri lajien hemiselluloosan koostumus todettiin hyvin samanlaiseksi tietyssä kasvuvaiheessa ja tietyssä kasvinosassa. Se näyttää olevan eräs kasvien kemialliseen taksonomiaan sopiva lajituntomerkki.

Canopy—coverage of shrubs and perennial herbs was determined on 44 relatively undistributed sites scattered throughout the vegetation mosaic covering valleys in southcentral Nevada. The dominant shrubs were Larrea divaricata, Grayia spinosa, Lycium andersonii, Coleogyne ramosissima, atriplex confertifolia, Artemisia tridentata, and A. arbuscula subsp. nova. Perennial herbs contributed little to canopy—coverage. The perennial herbs most frequently encountered were Oryzopsis hymenoides and Stipa speciosa. In the spring of 1960, on 34 of the same sites, the canopy—cover of annual herbs was also determined. Sites dominated by Larrea shrubs had more annual species and also the greatest amount of annual cover. Chaenactis stevioides was ubiquitous and often the dominant annual encountered throughout the vegetation mosaic. Other important annuals was Mentzelia veatchiana, Eriogonum maculatum, Eriophyllum pringlei, Bromus rubens, Cryptantha nevadenseis, C. circumscissa, and Amsinckia tessellata.